11 days off a month, 4 are "hard" or untouchable. The others can be moved (i.e. trip extended) but it's very rare. 5 days on would be common but it does vary a bit. You are assigned a protected time of 9 hours off the hook when you are on short call. Although you bid for protected times they can and commonly do change your protected time to suit their needs the day before so there is no consistency whatsoever.
Long call on the 190 is fairly senior. On the Airbus less so. 9 hour callout, but 95% of the time you will get your assignment by 1pm the day before when they process all the open time. It is possible for them to transition you to short call status with just 9 hours notice and almost no extra pay. Sucks, luckily it's also not all that common. More bad news for the long call guys is that you will get called quite a bit. Fairly common for long-call guys to fly 80 hours a month while the short call guys get 25 or 30. I went a whole month on short call once without getting called at all.
Essentially life on reserve for a commuter is not real great, nothing surprising there. If you live in base short reserve can be a good deal. The only saving grace for commuters given the crappy contract terms is that, in general, it seems like the schedulers are not out to intentionally screw you and will work with you a bit if you ask nicely (release you early from reserve on your last day etc.) Also commuting on mainline is not bad since you can reserve the jumpseat and you'll only get kicked off for a Fed or line check.