If I was going to buy a new trout rod, I would buy the G2 but in a 4 wt. I would use it for nymph’s and dries. I would use a 6 for streamers or in situations where it is super windy.
Just to make the picture a little more interesting, I noticed that Scott has reissued two G series rods as part of their Classic program. You can get the 8’4″ G in a 4 and 5 weights right now. I have fished both the G2 and the G (which I own in the 884 configuration) and like the G better. I like mine with an SA XPS line, although they tend to kink up a bit.
I like it’s moderate action which allows me to do almost anything. Most of the time I’ll be fishing multi rig nymphs. But casting dry flies is just point and go. It evens handles smaller streamers (woolly bugger, etc.) excellently.
A too fast a rod would make it a bit more difficult to cast a multi rig nymph without getting tangled. It’s the smooth acceleration that keeps them nice.