Aren't they more like almost $100/mo apart equally equipped and with taxes? For $50 I'd go for the classic inline 6 with more smooth power than you'll ever need on the street. At $100 it's a tougher call unless money isn't an object because the N26 really is adequate plus you'll cruise on the highway at 30+mpg regardless of your speed.
I will have the same dilemma later this year and since I think I prefer the new GC and with likely no lease programs I'll probably end up with the 428 for 335 money!