Have you personally had problems or are you just quoting something you read on the Internet? I have a couple of different model Lexar USB 3.0 card readers & all work perfectly in several Mac Pro 3,1s with a variety of USB 3.0 cards plus in my MBP 2008 with a USB 3.0 Expresscard.I'd avoid the Lexar USB 3.0 card reader, as that particular reader has had problems with USB 3.0 cards in Macs, and I think also one of the earlier USB 3.0 MacBook models.
Have you personally had problems or are you just quoting something you read on the Internet?
I have two models of Lexar card readerNo, if it was me I probably wouldn't say anything because it might be an isolated problem of my own doing.
Over in the big USB 3.0 thread there were several people complaining about it not working, or being very unreliable. Do a search for "Lexar" in that thread and there are two pages of results with numerous complaints about it.
Glad yours works. Perhaps there are multiple models and you might have a different one.
They both work fine when used with a variety of USB 3.0 Interface cards (Innatek 4004 & HighPoint RocketU 1144C plus some others) in several Mac Pro 3,1s.