I have a 2006 Classic with a turbo. I love it but I am a certified speed freak!
The bike is very "streetable" with the turbo. I'm used to Japanese fours and am pretty familiar with how they "feel". What amazes me about the turbo R3 is that the thing just never stops pulling!! I mean never! With the Jap fours I was used to pretty high RPM's and have had to realign my inner computer to shift at 6000-6500 RPM. The BEAST JUST KEEPS ON PULLING. All the way through 5th, or whenever your eyes get too big, or you're about to run out of road.
This is my first R3 so I have no previous comparisons. I love the way the bike handles too. I can corner much better than I expected and FAR BETTER than any of my friends on other "cruisers".
Usually bikes with turbos have a concern about "turbo lag". That's the time it takes for the turbo to "spool up" to begin adding power after beginning to open the throttle quickly. None evidenced here or too minimal to speak of. The R3s are already torque monsters and you really have to be looking for it to feel any turbo lag.
Turbo Connection is the folks who built the kit for my bike but it was all done before I bought the bike. I bought her about a month ago and she had just under 3600 miles when I got her. The Turbo Connection folks are very friendly and you can talk to a tech or the owner just about any time.
The exhaust does drone on me. It's not overly loud and the turbo itself acts as a partial baffle but it does drone on you. I'm looking into baffles that I will modify to get her quieted down. Not too much though. Friends who have ridden with me say I sound like Diesel Jake-Brake complete with turbo whine. I love it.
The others guys thoughts about warranty are correct. My bike had the kit installed by the dealer so they warranted what they chose. That shop is in New Hampshire and I live in Arkansas. I no longer have a factory warranty, I'm sure. The other thought about resale is also true. You will greatly narrow the field of potential buyers with a turbo on the bike. I don't plan on selling mine for quite a while so, for me, no big deal.