Yes, I have the 45tx, and it's remote is quite good. It has presets for every piece of equipment I've tried it with, but it also has a learning mode if you come across something it doesn't already know how to deal with. I'm a big fan of the design of this remote in general. Best one I've ever owned.
Yup - they both have learning remotes. I know the 43TX will learn for a TV & DVD player, but I can't vouch for how well it does a VCR or satellite. I was just too lazy to get it set up right for the satellite (mostly 'cause I'd previously found a relatively cheap-o multi-remote that did the satellite really well).