I've had no trouble with hesitation and I wouldn't worry about it for a second.
The MSP is actually relatively trouble free so far, IMHO. There are a couple of common problems, but they are minor (ie. the flash, replacing the rear sway bushings).
Most of the people around here that have had disasterous failures have been upping their boost.
There have been a couple of people who have had random problems with cars that haven't been modded, but that's inevitable with any type of car.
This applies to anyone that thinks the MSP has problems- please, please, please check vwvortex.com, focaljet.com's SVT section, b15sentra.net's spec v section or the website for any competitive car. Even the Civic Si has problems, which has to be frustrating since they bought a Honda and on top of that, the car is slow!
The Spec V's all have crunchy gearboxes. Those motors are N/A, but they chew through them like there's no tomorrow over there. The motors that don't blow, have major oil consumption issues.
The SVT Focus's clutches tend to fail prematurely, if they don't break loose and exit the transmission housing first (I'm not kidding, check focaljet.com, this is common). They have had not one, but FIVE flashes for the SVT Focus, and they still haven't gotten it right. The RPM's don't drop between shifts, there's surging in the midrange, revving engines when started cold and more. The dual stage intake cables on the SVT break. They released a revised part, it breaks too. People have been through this 2, 3, 4 times often. The heat shield for the cat falls off, but before it does, it vibrates like mad.
The VW's have failing ignition coils that leave you stranded or limping home, faulty window regulators that break and leave you with your window down and unable to close it. Bad transmissions are common. Fearsome electrical gremlins.
People like to run their mouths when their car breaks- and I don't blame them, it pisses me off too. You get a slanted view around any of these boards, however, as everyone uses them to gripe.
As for the SVT Focus being slow, its only a couple 10ths slower than the MSP either 0-60 or 1/4 mi and the handling is just about the same. The high revving motor is fun, the 6 speed transmission is slick (and much quieter on the highway) and the SVT is overall an easier car to drive because it has smoother power delivery and way less torque steer.
The downsides to that car- you're right about less room (although its offset by the added utility of a hatch), plus weak low end power. And reliability is questionable.
I own and love both.