I have a Sugar 3+ and a Cake 2. I like both bikes a lot. The Cake 2 is more plush ride and the Sugar is just a great bike. I prefer the regular Cake over the DLX version since the DLX has 5 inches and the 1,2,3 have 4 inches. I just think for XC that I do, 5 inches is too much.
So you can't really go wrong with either model...I'd go 2003 or later with the Sugar or 2005 or later with the Cake to avoid the Cake pivot issue. Just stay away from the DLX unless you are a freeriding jumper/downhiller.
I thought all cake models 1,2,3 and the DLX versions have have 5" of rear travel. I know the fiirst year they were made in '04 the difference between the regular cake and the DLX was the DLX came with disc brakes and 120mm to 130mm front forks instead of 100mm front fork on the regular Cake, but all had 5" rear travel.
As far as the pivot issues before 2005, I have a 2004 cake 3 (5" rear travel) that I use primarily when i ride the Tahoe rim trail (lots of black diamond drops). Bike floats down the chunk, climbs like a billy goat and stays on target in the singletracks. However, since it is a 'one pivot' single pivot suspension, you must dial in the rear shock to eliminate peddle bob.
I have replaced my front shock to rockshox recon 120mm, rear shock to fox rp23, switched to avid disc brakes, added easton xc II's wheel set and had the pivot rebuilt once. It is an almost ten year old bike so rebuilds/replacements are expected. Also, I weigh in at over 240lbs and do not take it easy on my equipment. I have only managed to dent the frame (1st year I owned the bike) and break some of the components, like both front and rear shocks, original peddals and bent the original rims, but the bike on the other hand is solid, well at least I can attest the '04 is, with it's true triangle frame, strong and stiff frame design.