Well, not having auto latency compensation does take some of the joy out of it, but the workaround is a latency comp plugin that you put on a sub buss, then route non Powercored tracks through the latency comp buss, and on to the stereo buss.
There are, of course, latency issues when using outboard hardware too, which generally require recording the return, and then sliding it back in time, which means no real time parameter adjustments. Even without auto latency comp, I find the Powercore stuff much easier to use than external hardware since it intigrates as a VST.
BTW, I use the PCI version. There's a new version coming out called Powercore element, which is the same card, minus the X3 (TC Finalizer) for close to half the cost of the original Powercore.
At around $500 street price, it's really something to think about.
Cheers, RD