I have a 525 PE. I like the knife but I don't use it much because of the aluminium handle. I prefer G-10 or micarta or FRN, depending on what I'm doing. The 525 is a great knife, though. I do carry mine some when I'm not at work.
As far as lubes go, I'm currently using Tuff-Glide. I've used Militec and Break-Free before, but I really like the dryness of Tuff-Glide... seems not to attract as much gunk.