I went with tactile and I was not disappointed. The feel is excellent. I only wish that I could choose the steady color. Blue is cool, but I prefer green and the experts in vision recommend red. Otherwise, buy this!
Prior to purchase I reviewed specifications and a user manual I came across showed the upper numeric row of keys (with shift characters) had 100% backlighting. The numeric keys on the G512 keyboard I received do not light up the shift characters, so using in a dark room without lights on makes it hard to enter shift characters. Talked with Logitech and they do not have replacement keys. If you need to type (or play games) in the dark, purchase a different keyboard with full 100% backlighting.