There don't appear to be any processing fees with these cheques. Every credit card I have seems to send low-interest cheques, usually lower than 2.99% and usually with extra fees attached. BTW, PCFinancial is paying 4.1% plus a small year-end bonus, which isn't a bad return on these cheques (still assuming there's no extra charges).
=aw
One has to be careful trying to take advantage of low interest rates on CCs. 2.99% invested at 3.75% (current ING rate) actually results in a loss after you pay tax on the interest if your marginal tax rate is above 20%.