Quentin,
For what it's worth, when my "new" 07 TBA was delivered from New Hampshire, I discovered she was lowered. More so than even what other members have done to their bike. I quickly discovered that going over things like RR tracks can be an interesting experience, like I feel I'm going to be thrown from my seat.
I just had some repairs made at my friendly local dealer and they included the following statement We feel that the bike is unsafe to ride with the forks and shocks modified. They even ensured I signed this statement. They also cautioned me about speed bumps, etc.

I was planning on replacing the the shortened 412's with stock Hagon Nitros and fixing the forks as well. So she won't be lowered for much longer. But if I were you, I'd give second thought to lowering the bike.

Just my 2 cents.

Blue/White 2007 TBA, Thruxton needles, Unifilter, AI removed, Polaris Bellmouth, Bubs, Nology Coils/wires, Lightbar, Ricor Intiminators, Hagon Nitros, Tall Sissy Bar w/luggage rack, Dart flyscreen & Lowers. 130 Mains, TrueGel Battery MG12-BS.