Pioneer is THE name for DJ gear and I personally wouldn't buy anything other. The 1000's aren't the industry standard for nothing!
I'm still using my beginner setup which includes two CDJ-200's, I've been using those for a couple of years and I love them. I wouldn't mind an upgrade but not for any particular reason. I use Serato, so I really only need something that can play CD's and has a pitch slider

Personally the 900's are too much for me. I only need something simple, so I would go for 1000MK3's if I were buying something for myself.
If you need features that the 900's offer then perfect, as long as you are looking at Pioneer then I think you'll make the right choice. Even my 200's are AWESOME! I love them! I highly recommend Pioneer.