I just finished paramedic and took a "standard" course that was 10 months long. It was about 60-70 hours a week, including homework/study, with about 2 weeks off at Christmas, but I don't remember having any other holiday's off. The last month, study went up to about 80-90 hours a week. You had to get an 80% minimum on everything. The teachers were excellent, but we lost a LOT of people (about 70% of the class) along the way. 3 other local schools also lost the same rate or more, but students only had to get a 67% or 70% on everything. Getting an 80% on every FISDAP the first time through was hard. But, I studied my butt off and did it.
I say all of this to say, the normal school route is excruciatingly hard. Contrary to Internet wisdom, schools around here with higher pass rates don't seem to have better teachers (all that I'm familiar with have been excellent), but merely easier standards. If I had prior experience as an 18D or a nurse or something, I would take an accelerated course hands down. It would just be an easy refresher. If you can read or hear something once and remember it forever, I would take an accelerated course. If you have no problem with 70-100 hours a week for 6 months, I would take an accelerated course.
If not, remember that a standard course is hard enough. Some that were 10-12 months and 640 hours are now 10-12 months and 1,500-2,000 hours. I saw my girlfriend one night every other week and didn't sleep for a year and I took a standard course.