Where are you coming from and why Ontario? I have had seasons passes to Blue Mountain for years, so hopefully I can offer you some more accurate advice than what's been posted. If you're deciding on Ontario, Blue is pretty much the only mountain/hill worth going to. The vert is 720 ft, Searchmont near Sault St. Marie is 700 feet or so. Nothing else anywhere near that in Ontario (other than the private clubs beside Blue Mountain)
1) There are 4 high speed 6 man lifts... I would avoid weekends but week days they pump you up the hill. I'm looking at my GPS tracking now and I averaged about 13-15 km/h at blue (that's uphill and downhill combined) which is the same as any of the big mountains I've hit in Alberta/BC and better than some of those. So for sheer quantity of boarding Blue is great.
2) Again, I'm looking at my GPS records now. I'm a bomber and it's about 1 minute a run at full tilt, not 1 minute or less. Mid-week there are no lift lines so about 5 mins up, minute down, do it all again.
3) I've usually boarded from Mid-December to early April there. I heard this year most of North America was closed early, so can't speak for this year. Most years my last days were in the first week of April. By then it's full on spring conditions. The last "good" snowboarding would usually be mid-march.
4) It does have a decent night life if you stay on the hill. The Blue Mountain Inn is the cheaper route, and if you get the food + hotel package the food is quite good at the Pottery. Staying in the village you get smaller, but more modern rooms, and a nicer hot tub area outside.
Overall, I wouldn't specifically drive to Blue Mountain if I could spend a little more travel time and get to anything in New England, Quebec, or hop on a plane and come to the wild west! But for people in the Toronto area, Blue's pretty decent.