Although I have years upon years of tabletop roleplaying experience and a couple of recent years of playing roleplaying games via Fantasy Grounds (a VTT), it hasn't been until the last few weeks that I've actually had the opportunity to sit at a table and game AND sit at my computer screen and game (using an actual RPG) during the same week.
The experience, at least with Google+ Hangout, is strangely similar. Same bad jokes (at least coming from my direction), similar excitement when the party overcomes a dangerous obstical, you get to see facial expressions (which can be preceless) - the list can go on.
There are some major differences. Dice rolling is NOT the same. Using an online die roller vs. chucking your own is definitely second place. As for the voice part, you do tend to talk over others using G+.
Still, both are heads and shoulders over not playing, or playing a MMORPG. Just sayin'.