I don't think you are really switching, but rather learning a new opening. Because you cannot control your opponent, I would recommend being familiar (but not necessarily knowing indepth) with how to play e4 and d4 as well as c4 and Nf3.
Switching from e4 to d4 (or d4 to e4)
I did it. Queen's gambit has so many interesting rich positions that it can offer both positional and tactical play. Also you are avoiding ruy lopez, sicilian. Imo my encounters rely more on understanding the strategical ideas when I open with d4. E4 was a lot more tactical but sometimes I transpose into e4 openings still ( after 1..e6), after 1...c6 I normally go 2. c4.
If you are a very new player I would use it but not all the time, you don't want to limit your chess experience over long periods.
switch the second you feel like it.
Many people play e4 because it is recomended for begineers to learn sharp postions. Some of these people never move out of this which is okay but I think exposure to different positions is good.
I play both but no one is reviewing my games at the tournaments I go to lol...
Anyway I do keep things simple. I'm not bothering with hyper-theoretical things like the bayonette attack or the poisoned pawn variation.
switch the second you feel like it.
Many people play e4 because it is recomended for begineers to learn sharp postions. Some of these people never move out of this which is okay but I think exposure to different positions is good.
I was informed the opposite. Learn d4 because if you make a novelty move (okay, blunder), your position won't be as devistating.
I agree with AaronGo. Anyway, strangely enough I haven't switched in years, and I don't really miss 1 e4. I guess d4 just suits my style. I don't think a player should feel like they have to switch -- one could study either move for a lifetime. And there is plenty of room to deviate within 1 e4 and 1 d4 lines. I don't feel like I'm missing out or anything -- regardless of the opening, chess is rich enough that you'll still encounter all sorts of different types of positions. So you might as well open with what makes you the most comfortable.
Thanks for the replies.
Part of my reasoning went, if my focus is to learn more about chess, then I should look for ways to step outside my comfort zone and get middlegame positions I don't really understand or I'm not comfortable with. Yeah in the short term my rating may drop, but not really concerned with that. If I stay in my comfort zone I may set up road blocks by mis evaluating certain types of positions over and over (by misusing logic that works in most positions I get).
Any experienced players ever do this and want to share the pros and cons? Is it worth it to expose yourself to more chess positions / ideas? If exposing yourself to new ideas is your goal, if you're under a certain rating is it not worth considering?
I'm considering switching from 1.e4 to 1.d4
I did it a couple of years ago. I used Cox's very ambitious Starting Out 1.d4 as my repertoire baseline. The advantage is that it features pretty sharp stuff, so I didn't switch from 'initiative play' to 'technical space grabbing' immediately (I'm now at this stage).
In general, I found playing 1.d4 with a lookout for sharp play often takes opponents by surprise, and I got a tremendous score against people in the 1800-2000 range (unfortunately, I don't play many people in the 2000-2200 range, and against those guys I usually sticked to my 1.e4 guns).
This kind of repertoire change certainly broadens your horizons, and I feel a more complete chess player now. Unfortunately, results-wise, I can't say I've made huge progress because of the change, but I didn't regress either 
To be honest, it isn't really "switching". My opinion, btw. I think of it ad transitioning. Because in most cases, as some here have eluded to, maybe you feel you have gotten all that you can playing e4. Dunno. For me, I still play e4 once in awhile, but mostly out of nostalgia. I played it when I first started out (it's almost compulsory methinks) and like most things in life for most people, you grow out of it and turn to more sophisticated openings. With all of its subtle nuances, positional complexities and pre-emptive endgame themes...man, how could one go back to the ol' slash n burn, "i know a line that you don't know", risky positions again?
Heh. You got me.
Anyways. Just playing an opening simply because you want to "get out of your comfortzone" seems abit naive. I like ta play openings within my comfortzone. Meaning, I want to be the one inflicting discomfort (on my opponents) instead of doing it to myself. That's just me though.
If "switching" is what you feel, then, who is anyone to say otherwise?
8)
We all like playing positions in our comfort zone, of course!
I just feel like the more positions I expose myself to, the more I'll have the opportunity to learn. Often I'll cut off analysis of "odd" structures or plans simply because I don't recognize or am uncomfortable with them. I feel like if I always steer the game towards what I understand (or maybe I should say, am currently comfortable with) then I can't get much better than I am now.
Post #14: I don't really see it that way. I think there will always be plenty of things you're doing wrong regardless of what position you're in :)
For example, any sharp position can become solid; any solid position can become sharp. Say you develop a huge positional bind; if your opponent puts up good defense, your best bet may be to transition into a winning but tricky endgame that will feature all sorts of tactical tricks. Having a good opening just sort of gives you a headstart, starting with a position you already know to help you out. Most of the game is still played in the middlegame and endgame.
...but I think the OP is already at a level where the study of the opening goes beyond the first moves... 
every once in a while i'll play d4, but e4 is my main start. There are so many options just by playing d4 and e4, why change if you don't want to? I like playing against the Sicilian, play the Scotch,Scotch Gambit, Italian Game, etc. Sure everyonce in a while you should do something else, but no reason to change completetly, unless you want to.
Post #17: You seem to be missing the point, as that has nothing to do with what I'm saying. You can analyze an opening out far, sure. In general, most of the chess and thinking you're doing still is not pre-done. And you will still get plenty of sharp and solid positions inevitably (as in my example in my previous post).


Any experienced players ever do this and want to share the pros and cons? Is it worth it to expose yourself to more chess positions / ideas? If exposing yourself to new ideas is your goal, if you're under a certain rating is it not worth considering?
I'm considering switching from 1.e4 to 1.d4