I had a chance to use a 12" flextube with GOTO for a night at the SPSP and I've got to say that it was the `drag n' track aspect that I loved the most.
GOTO seemed to work well enough but for most objects i simply pushed the scope manually onto the object and it tracked automatically - no fiddling with clutches as you do with a Servocat. A tracking dob is a great thing- and tracking that is completely transparent is an even greater thing
So if I had a $2500 budget I would go for GOTO Skywatcher 12" and a light shroud.