I've had a Boxster S before the Elise and drove the TT in front and Quattro forms, however, I can't comment on the Cobalt.

The Elise does feel like a go cart. For better AND or worse yes, it does. That means it changes direction very quickly and feels very nimble. That's good for tight circuits but not makes the car feel a bit twitchy. A Boxster is easier to drive and more stable. The Elise can be faster but requires more skill (and definitely more precision) and definitely makes you feel more connected to the road. Feedback is the Lotus' strong point.

As for the TT, its weakness is an overly light steering feel and lack of feedback -at least compared to the Elise and Boxster. The TTS may have a stiffer suspension but the interface between drive and car is the problem.

The Boxster would be in between the Elise and TT. I think the limits are higher on the Elise than a Boxster but the tire conditions would need to be right on the Elise like: a) A048 Yokohama's need to be warmed up at operating temps (hard to do on the streets); b) they can't be heat cycled out (means less that 5,000 miles old). So, the Elise has a narrow margin for it to perform exceptionally well. When my A048 worn out, I had a hard time keep up with Accords in the canyons.

Lastly, I don't think you can make the assumption that a TTS can beat a Elise just because the Cobalt can beat an Elise. I'm not really defending the Elise. If I was I'd still have one. I'm just point out the strength and weakness of each car. Maybe a good analogy would be a Porsche 911 vs. a GTR. Reports say the GTR is easiy to drive fast while the 911's rear weight basis makes it more challenging to drive.

PS: On a side note, I do think the Elise needs a redesign. The platform dates back to 1995/1996 and got the current update in 2000 (Europe). Supercharging helps but technology has caught up with the "add lightness philosophy".