well, from what I've read, the quality seems to have improved considerably over the years. Most agree though that the quality of fittings and finish is somewhat variable whilst the blades are generally held to be well tempered.
I own one of their 15thC longswords
http://www.kultofathena.com/product~ite ... gsword.htm
Whilst the sword is pretty enough, it suffers from three annoying faults; first it handles like a shovel, down to poor blade geometry I'd guess though I'm making no pretense to expertise. Second, Windlass insist on using a really tough laquer on some of their blades which is hideous, makes the blade look like its chromed or something. Third, Most of the long Windlass swords suffer from floppy blades, you'll find reviewers referring to "floppy choppers".
Oh, one last thing many sites sell 'em as "battle ready", they're not. I would say that a bit of casual backyard water bottle or pool noodle cutting is about what these swords could safely handle, even then I'd be careful; a lot of the pommels are screwed on ( five sixteenths Whitworth, I think mine is) and are known to work loose. More alarmingly, the wood forming the handle of mine was shite, poorly formed and cracking. I only found out 'cause I stripped the leather of whilst taking it to bits. If I'd given it any welly it may well have failed catastrophically. Mine may have been a lemon but you never know.
The only plus for me is that I'm left with a fairly decent blade which Is going to have the laquer bead-blasted off it, them I'm going to shorten it and have a go at some home customization.