The ONLY downside to the setting IMO is the naming conventions. Wow, Kalamar has some jarringly difficult to pronounce names. Names that are strange sounding for the sake of being strange sounding...kind of like the way a less than steller fantasy author would create. I'm not insulting the creators, but one of my peeves is naming conventions and Kalamar's naming conventions are IMO some of the worst. I am however very picky about such things so you can't necessarily judge using my point of view.
Give it a try.
Wyrmshadows
Unfortunately, the names became a showstopper for my group.
It took a few sessions, but then my players asked to play in a different world, where the names weren't so obviously created with a random generator.
Myself, I had noticed the problem, but hoped that the upsides of the setting coulkd compensate, but no. (I guess the plausible looking maps and atlases were something Kenzer could sell to DMs only).
Opening my Atlas on a random page (page 132) names include Pijkkurzagh, Thizhahagh, Lekkzhawazh, Khoviggazh and Thakakkazh. It quickly becomes all a blur.
But okay, those names are Orc. Let's flick to another page, uhhm... page 108! Oh, nothing but open ocean, okay...
Page 51! Okay, this is where Bet Kalamar itself resides, so no funny Orc names here.
However, the names still blur to the point of becoming indistinguishable... Sowido, Gobido, Livowido, Vevusido, Merido, Sika'ido, Rilido, Kuvido, Wirido, Tumufido, Naka'akido, Hudepido, Mothisefido, Polido, Thimido, Rogido, Ruwido, ... okay I'm going to stop here, my head hurts.
(I'm going to apologize in advance for any misspellings which I'm sure I can't have avoided)
It makes me long for the days of faux-english names (Evilstown, Cape Death, Saint Good...

) and it makes me realize my players were right.
There may well be a lot of scholarly research behind the Kalamar campaign world, but it must have been confined to mostly the natural sciences - there certainly have been no professor Tolkien around to tell the authors their names suck, and badly at that.