I bought it and am wondering if it can be used in conjunction with phoenix or cgminer?
It's planned in the future, but at the moment only with poclbm.
Thats what I was thinking. I don't know if that would be the most profitable, but I have to think sticking with one pool that is slow and only getting a few shares in on faster pools isn't the most profitable. Over on the bithopper thread they are all trying to implement "slicing" which basically tells the hopper that if there is more than 1 pool under 43% to rotate between them submitting shares. Again, there are people a lot smarter than me who know what is the most profitable though.
The earlier shares are most profitable afaik. I wanted to release 0.6.4 today but I'll delay it a bit longer to add this mode that takes hashrate into account. The next version will have 2 prop pool hopping modes to choose from, picking fast pools first or this regular one.