sigerson | Seeking advice: Twonky and daycare

Today I cold-called about twenty local daycare centers (family and group) to ask about availability in January. While I found out some good information and have a few leads, talking with

sen_no_ongaku made me realize: We don't know what we're really looking for in a daycare.

We don't know what things are must-haves, what things are nice-to-have but not essential, what things are entirely irrelevant. Distance from home? Accessibility to T? Flexible hours or strict pickup policies? Number of caretakers? Kinds of toys and activities? Hourly rates? Lots of kids or few kids?

So I'm asking the parents out there who have used daycare: What have been the best things and worst things about the place(s) you've used? What is your sine qua non? What things have you really liked but could live without?

I don't expect consensus, of course, nor do I expect to be wanting the same things--but right now, we don't really know where to start. So, internets: any advice?