pay the little extra and get the best quality machine you can afford. it will last you years. the drop weight with 6 point mount, fixed clamps and linear gripper is probably the most accurate machine you can buy. and it hardly needs maintenance (less than lock outs or electrics anyway). might not be the fastest but what's 15 min per frame when you do it for yourself anyway?
i've had a gamma drop weight 6 point mount and the only 2 things i regret about my machine are 1) it has cheap flying clamps 2) rotational gripper which can kink some polys. all in all though, mine has paid for itself many times over and has been very reliable. can't complain at all.