I drove both a week ago in automatic, hatch form, back to back.
I found the 2.3 superior in performance, although not astonishingly so. This is in line with the reviewers.
Surprisingly, I also found the 2.3 quieter as I had to work the 2.0 very, very hard to get anything like the performance I am used to (my current car isn't flash but it does have a 3 litre V6). I felt I had to work the 2.3 pretty hard, too, but it did respond nicely and had just the right amount of torque I was looking for. Both engines rev freely up to red line even in AT form. I'm not used to that but I guess modern 4 cylinder engines do that sort of thing. Fun.
Also, FWIW, the 2.3 on PULP has more performance improvement potential, if you are interested. I was reassured both cars were not running on PULP during the test drive. According to the stickers the 2.3 chews through 0.5 litres more fuel / 100 kms.
As for interior trim, I prefer the Maxx over the SP's blue but I like the SP's red. I dislike the SP's carbon fibre dashboard strip.
I have always driven rear-wheel drive cars and was pleasantly surprised with the handling of both models. With the kind of mostly law-abiding city driving I do I wouldn't choose one over the other on handling.
Just as an indication on pricing, I have been quoted off the cuff a Maxx @ 30.5k and an SP @ 35 drive away. On cost, I've looked up redbook and it seems the old SP20's depreciation stays healthier than the standard model. Time will tell if we see the same trend with the SP23.
My decision comes down to torque and a fortunate budget that can wear a 4.5k price difference.
Anyway, for those reasons, if I get an MZ3, it will be a SP23. And I don't see any current competitor that will have me going elsewhere. I went to a toyota yard determined to test drive a corolla but after sitting in it I just didn't have the stomach to bother taking it for a drive. It feels old. And the astra and golf have new models coming out this year. I would wait if I could, as they're likely to provide keen competition.
I would
strongly advise test driving both to see what suits you in the performance/cost trade off. I'm confident you'll agree both are top of their class. Please furnish us with your thoughts when you do.
