Yeah, OP's configuration looks fine to me. Pretty sure that's an ASM1166+JMB575 card, PCIe3x2 which should give a max (theoretical) throughput of 2000MB/s, and he only has 5 drives connected so he should have headroom. It might be prudent to figure out which ports are being multiplied by the JMB575 and avoid using those, but otherwise this card should be perfectly fine as long as you don't fill up the ports or connect any SSDs to it.
LSI SAS cards have been the standard for a long time because until a couple years ago you could only really get PCIe Gen2 SATA expanders, and while a lot of them were great a lot of them were awful especially when you do something stupid like connecting 8 drives to PCIe2x1. You didn't (and still don't) really see any SATA cards that use x16 for some reason so SAS was the only realistic way to not get bottlenecked and really stress the card.