Actually, in reading some reviews...it sounds like the SRT-4 is possibly road car than the Sentra.
"Inhaling a track or mountain pass, that's where the SRT-4 wants to be. It resolutely glues all four to the corners, displaying none of the wild tail wagging we noted in the R/T."
vs the SE-R:
"The car stuck through the course through curves, but the breakaway point was never easy to pin down and wholly unforgettable once it was hit. Under braking,..., the rear end was always fidgeting."
(C&D, May 2003)
However, looking at some more recent reviews (I think Road&Track takes the 2004 models out this month) it sounds like the Sentra has had its suspension tuned up considerably, and the SRT-4 tuned down.
Sentra:
"Immediately after turn-in, the rest of the car smoothly follows the front's lead with confidence. There's noticeably less roll than stock and even with a foot full of mid-turn throttle, the S-Tune's front end keeps clawing its way around the corner."
SRT-4:
"Go around a corner, however, and this beast's chassis shows its vulnerable underbelly. With way more engine than suspension, it takes some work to go around a corner smoothly. Come in too fast and excessive body roll makes it hard to turn in. Get on the gas too soon and, despite its Quaife limited-slip differential, the front end wants to push off the outside of the turn. "
(R&T, August 2004)
Make what you will of car reviews - I suspect it has to do as much with the driver as anything. Maybe the Road and Track guys just couldn't get the hang of the Dodge. I've only driven a 2003 SRT-4, and it's a badass machine on the straights or in the curves. I'd be hard pressed to find real weakpoints in either of these, but I'm far from a good driver, so perhaps the subtle differences would be more obvious to some of the more experienced racers here.