If I want a cosmetic, working elevator, I love the RFTools option. If I want a quick way to travel large vertical distances quickly, I usually use the OpenBlocks style elevator. I've not played with Thuts, so I have no vote there. On the whole, I enjoy the challenges that RFTools inspires me to do - proper elevator shaft, power, screens, safety doors, and the whole shebang. This is particularly true because most of it isn't required, except for my personal sanity, which forces me to try to pretty up the rest of my hovel to keep up.
I have played with the Slingshot and Slime Boots (add a Hangglider for traveling larger distances) and have to say it's hilariously fun.
Travel Anchors are a fun way to make a base with no hallways, but I rarely use them in a conventional base setting. Still, options are good.