For the money, I think the Pioneers are much better investment. I think the infinity speakers are in a weird price segment situation. It seems they are arguable not better than the pioneers and at a higher price point. Gathered from my readings here, for a little more than the primus, you get significant upgrade in HSUs, Ascend, Arx, Cambridge. If Primus match the Pioneers in price, you have a debate. At current prices, Pioneers no contest. At least that's how I see it or have analyzed from my research. I do not have first hand experience with he Primus, but Pioneers would not disappoint. They were a huge upgrade from my onkyos HTIB.
Yamaha RX-V673 | HSU HC-1 MK2 | HSU HB-1 MK2 - LR | Pioneer SP-BS22-SLR | BIC RtR-V44-2 (Presence)