Well we shall see.....I'm pretty happy with my kinda classic style looking bike. That still has some modern touches to it to round it out. If I get that exhaust well.....it'll kill my retro look-style I'm happy with (I currently have the twin slash slip ons and love them). I just like change every now and then, but $750 worth of "change" is a lot of money .
They sound great! Their looks is very subjective. I like how they don't look like anything else on the street. And most importantly: they look raw like the bike does.
The V&H Grenades, like any pipe, will appease some. Others will not like them. It comes down to personal preference. With the look I'm going for on my '14 48, I will be using these pipes with a flat black air cleaner. I think the pipes look best with a street fight/brawler/bomber style of bike. The 48 is a good base for this style. Couple the pipes in black (or chrome with header wraps), 170mm-180mm tires, and black out the bike, and you will have, in my opinion, a sick looking bike.
It all comes down to personal taste, your budget, and what your end goal is for the bike.
There are a few videos on YouTube. A poster above linked a few. There is also a review by Revzilla.com on the pipes with a sound clip of the pipes at idle and in action.
I think they would look great on my café bike, but they don't fit with my rearsets. I'm also conflicted by the unequal headpipe length, but that's a bigger deal for performance engines. Probably not noticeable on a stock motor.