What I'm about to propose may not be suitable for many, but for those with modest requirements & small(ish) machines, I'd say it's a much better alternative to the awful TB6560s.

i have an easy cnc 3 axis board....which is based on Allegro A3977 ICs (quite a decent IC) & it performs well - that said it's not particularly cheap. I recently needed a couple of axises (for a pickup winder), and noticed a bare bones A3977 driver boards can be bought for a good price...

http://www.ebay.co.uk/itm/M100-singl...item35baa0386b (bearing in mind the A3977 itself costs about £6. That seller did me two boards for $32 delivered

Yes, if you're a mach3 user, you'll need a breakout board, but I'd imagine the results with these boards will be far better than a Tb6560 - also, A3977s are far easier obtainable than a 3 week wait from china.

If you've the dosh I'd say just go for any of the the 542 drivers that abound everywhere (eg http://www.ebay.co.uk/itm/H-bridge-C...item4600f68e0f ), but if youre a bit strapped than my proposal above is a decent option.