The upgraded engine and tranny are just two of the updates made for '07. The touring models also got the maintenance updates first rolled out on the '06 Dynas - automatic primary tensioner, fully enclosed oil lines, etc. In addition, there were a ton of smaller updates for '07 - clutch interlock switch, clock, upgraded oiling system, yada yada yada.

Unless you're getting a helluva deal on an '06 (and you should this late in the '07 model year), I would go with an '07.

But it's your money.... There really is no right or wrong answer.

My $.02