Although the surprise element of unusual openings are nice, don't play an unusual opening, for the sake of it being an unusual opening. If you play the grob, like it, and are successful with it, go ahead!
However, if you repeatedly play it in OTB chess, don't expect to keep the surprise element for long =). Not only will your opponents eventually look up the line, they will get a feel for the line after playing you. If you really want to surprise your opponents, use it sparingly.
I heard that this opening, though ugly looking, can be strong surprise weapon in blitz, especially if your opponent is not familiar with its hidden tactics. On the other hand, it is really ugly looking. So if you have some common themes, weak spots in black's position, specific grob lines and nasty traps I would like that you share it with me.
http://www.logicalchess.com/resources/openings/grob/ offers some introduction and nice PGNs but I want to know more to decide if it is worthy to switch from KG to grob against some opponents in 3 0 or 5 0 OTB games.
Thanks for your advice in advance
P. S. If you know the link to some old grob threads, post it, please !