Bullet will not improve your Chess. It will only improve your Bullet.
Improving your skill: Do fast games help more than regular/slow games?

Bullet will not improve your Chess. It will only improve your Bullet.
How true.
But you can improve by playing 15m+10s.


Blitz games help you improve your tactical and calculation ability, because you have to calculate fastly ! BUT, standard games help you improve your general playing. You improve in strategy, calculation, endgame etc. So, of you have the time, I think you should prefer playing long time games
My opinion

I was recently adviced to play lots more bullet games than online games. What do you think? Do fast games have a better impact on your overall skill?
No. In fact their impact is negative. Blitz and "standard" can be good types of speed chess for practice games though.

What you need to do to improve is to know what mistakes you make and then try and correct these mistakes. Most players do not know what mistakes they make. [they may know obvious mistakes] So to become better record some of your games and then find a way to see what mistakes you made.
In bullet you are going to make a mistake about every other move.
If you play slower you will still make a lot of mistakes but you can learn from your mistakes.

If you are not very good, bullet will help you a lot of improving your chess skills. It helped me to find double attacks,checks, pinns, fast ( the basic technics that will make u a bit of better in chess, and yes I wasnt very good previous year (1100) ). It can also help you to improve at 1 opening. If you studied 1 opening, it is usefull to play the first moves fast cos u have to know what to do. But if you already are very good at chess, bullet wont help you to improve I think. But this is my view of it ;)

I was recently adviced to play lots more bullet games than online games. What do you think? Do fast games have a better impact on your overall skill?
That advice is absolutely horrible! Bullet is based on chance and luck with pre-moves. Tossing pieces around the board as quickly as possible is not chess, it's gambling.
Getting into the kiss of death habit of moving too fast is a fantastic way to destroy your game.
Chess is about thinking, about analyzing a position, thinking through the lines and finding the best line, or at least a good line and this takes time of course, which bullet doesn't provide.
Stay away from bullet!

I think there are many people with a low concentration so I think playing fast games is a good way to improve chess cos it is a quality to find good moves fast. I think its boring to look 15mins to 1 position.

I think there are many people with a low concentration so I think playing fast games is a good way to improve chess cos it is a quality to find good moves fast. I think its boring to look 15mins to 1 position.
Good moves can't be found in seconds or even less. If you have a problem with an attention span, chess isn't for you.

Bullet, I imagine, tests your reflexes; it doesn't train them, it tests them. To train your reflexes requires, as ponz111 points out, slow play and post game analysis. You can use fast chess to test whether you have learned the lessons you accessed in your analysis of slow games. Of course, you could also check how well you learned by continuing to play slow.
But the short answer is, slow+ analysis increases the possibility of finding the correct moves to make; fast tests whether you can make those correct moves at speed. Fast without slow doesn't permit you to ever increase your chance of finding correct moves, and so, a mono-diet of fast will guarantee that you do not rise above a certain level. That level, of course, will be 'your current level minus any drops that occur' by continuing on that faulty regimen.

I think there are many people with a low concentration so I think playing fast games is a good way to improve chess cos it is a quality to find good moves fast. I think its boring to look 15mins to 1 position.
It's not improving the quality of moves, just threat detection. Bullet chess is basically identifying threats quickly. If you can make threats faster than your opponent can respond (and if you can win an overwhelmingly won game with all pre moves) then you'll win a lot in bullet.
Making threats may or may not be useful in non-bullet games though. You have to actually think about the position.
Identifying threats quickly is the only skill I'd say bullet improves... and if you play long games then it's not a very useful skill to have.

That s true but I think everyone can find a good move after staring 15mins to a position. I think its very frustating to wait a few minutes for a move in live chess.
I was recently adviced to play lots more bullet games than online games. What do you think? Do fast games have a better impact on your overall skill?