I do trust bitvest but I don't like it that they take a percentage on every bet.
you have more risk here to lose on your investment
so far i have invested a little bit on betking and i have to say i am quite happy with their investment. I manage to profit even after the deduct of the fee. And it is a one time deduction unless you have new profit for the next month. To me, the most important is the amount of daily wages cause even if there is another sites with no fee but there is hardly anyone playing, you totally cant gain anything.