Bear hunting in the spring produces better numbers no doubt, especially over bait. Not to mention less things to hunt so it makes for a nice change of pace. That said fall hunting produces better coats and bigger bears (if you can get on them). Baiting this time of year is more difficult b/c of natural food sources but it can be awesome if a poor berry patch, lack of crop or early frost as well.
Another positive with spring hunts is that the breeding season is in late May-early June.
Up here in many places I hunt this time is also when the larger boars are rubbed and since many want a rug..I would consider this a negative. but it does depend on the spring/weather and area like anything else.