I take it you have a curvy, then the Falco will be a bit less comfortable (for a 173cm rider). But still ok,
I commute on mine and there's a fair bit of stops involved so I'm getting about 100-110 miles from a tank (reserve light leaves you with around 4L left) that's about 33mpg.
A nice twisty run the other weekend gave me 140 miles (41mpg) I don't know how Gr33k does it, maybe his is set up better or we use different mpg calculators

Get a proper test run, you'll see.
The other thing is, make sure it's set up properly. When I got mine it was set up for 2 and giving me a sore back after 10 miles :/
Places worth looking are:
http://www.ridersite.ws/rs/viewforum.php?f=20
http://www.apriliaforum.com/forums/f...splay.php?f=60
There are often nice SL's going for silly money...
Good luck