This has been hashed out quite a bit if you take the time to search, but in brief, cam locks are cheaper, require two handed operation and the ones with built in barbs have a small ID that may restrict flow.
QD's can be operated with one hand (if you can take the heat!) and have a lower profile but are more expensive.
I think most end up choosing the cam locks because they are cheaper.
I got my QD's from www.watercannon.com they were a good bit less expensive than anywhere else I could find them. I paired them with 5/8 brass barb fittings for wide open flow and they work great at a reasonable price.
I've never used QD's, but I can't find any problems with my camlocks. Other than ordering camlocks with the 1/2" barbs. If you don't do that, then you're golden.
I followed Bobby_M's advice & ground the threads off the 1/2" MPT connectors. Use a clamp to secure the silicone tubing. Works great & doesn't have the flow restriction of the barbed threads.