Out of those 3, I would stick with betcbs. They the only book I would trust right now that are offering 20% on all reloads. You win there, you WILL get paid , no questions asked.
You are safe at all 3 of them with cbs being the best of the 3. Guardian only allows one neteller payout per week and platinum puts a 30 day hold on any payouts unless you forfeit the bonus but yet even if you do forfeit it, you can redeposit and get the bonus back apparently.