for me, the ib was definitely worth it.
cas never really bothered me - it just seemed to do itself. the big thing with the ee is that you should start research early and have a 1st draft done before you start year 2 of the ib. that way, if you're workload in year 2 (the important year) is too difficult, you don't have to worry about writing an entire research essay; but, rather, about fine tuning the already completed 1st draft.
i finished the ib this year and am off to university, so i can't comment on how well prepared i am. what i do know is that the ib defnitely helped me get into my choices in canada (where i'm from) and the uk (where i applied as well)
for university admissions, i found the entering grade required to get into the top canadian and uk schools weren't that difficult, challenging but not everly-difficult, (top canadadian schools needed high 30s, oxford and lse (i didn't apply to cambridge) needed similar grades) - both groups of universities seemed to look very favourably on ib students.
plus, you get transfer credits at some universities for the course you completed at higher level and obtained an okay grade in (usually a 5.
on the whole, the ib was definitely worth it!