My math experiences have ranged from very positive to terrible, so here's a quick summation:

Math 127 (Precalculus II): Good class, four exams, and the lowest one was dropped. We had to do proofs, but were forewarned which ones we'd be tested on, so I basically wrote them over and over again, sometimes even using alternate methods, until I felt confident about them. Calculator wasn't that important, didn't help because it was mostly conceptual work.

Stat 491 (Statistics for Sciences): This one, a calculator REALLY helped. All students were allowed to use Excel, Minitab Solutions, a standard equations sheet ripped from the textbook, and any calculator we wanted on exams (which were computerized). I programmed some of the more complicated functions (hypergeometric dist., for some reason wasn't preloaded on my graphing calculator) to save time. Homework counted for 20 percent, which was great.

Math 181 (Calculus I): Horrible experience. About 40 percent of the class failed the first test, after that the professor banned calculators, which he termed "the magic boxes". I got a 30 percent for using the chain rule, because he hadn't gone over it yet, even though I ended up with the correct answer. Ended up dropping, retaking next summer (with different prof.) Calculator didn't really help much here.