Carib would be well down my list when it comes to recommending books. They're legit and worthwhile as a secondary out, but there are so many better books. My main gripes with Carib are
1. They post delayed odds. Use them for any extended amount of time and you'll understand what i mean.
2. No free Neteller withdrawals under any circumstances. At the minimum, they could offer a free withdrawal every x number of days like many other books do. Even worse, if you want to withdraw more than $2500, you need to pay multiple withdrawal fees. If Carib was a reduced vig book, I'd be more understanding here; but they're not.
3. 20 cent lines for baseball. Even Olympic has seen the light and gone to a 10 cent line.
4. Slow site. I'm not referring to the DOS attacks which affected many books. I just find Carib's site slow in general -- relative to other books I use.
On the plus side, they do have a nice selection of offerings. Plus, their customer support is very polite and quick to respond.
Who would I recommend?
IMO, Pinnacle is by far the top book out there. Lowest vig around and never a concern with them. Very tough book to beat though. There's a reason they can afford to charge low vig -- sharpest book out there.
Of sponsors here, I would put Olympic next, especially now that they've gone to a 10 cent baseball line. They're typically the first to post lines and have numerous offerings. My only gripe with Olympic is their high vig on props and futures. But, all in all, this is one of the top books out there.
Although I haven't yet used 5dimes (I plan to soon), I've heard nothing but good things about them. 5 cent overnight lines for baseball along with numerous offerings.
Although WSEX doesn't seem to get mentioned much amongst the top books, I've always liked them a lot. Unique interactive wagering and can often get good dog prices here.
Canbet used to be higher on my list. But they are on the paranoid side. Win too much and they will reduce your limits. They advertise low vig, but they use a different scale than most books. Once the money line reaches a certain threshold, their vig is actually on the high side. But -107 is nice for your standard pointspread sports.
There are several other non-sponsor books I use. Of them, I would rate Hollywood and IIS at Olympic's level, 2nd only to Pinnacle. I'm never sure how much I'm allowed to say here. Hopefully, it's ok to mention non-sponsor books as long as I don't post URL's for them. If this is not allowed, then I'm sure an admin will edit my post.
Overall, I use or have used about 15-20 books. I'd put Carib about 10th on my list.