I have the Indivision ECS on both my A500 and A2000, and would never go back. Indivision offers a much "cleaner" and "more modern" "integrated" approach to upgrading Amiga video output. It also directly supports someone who's done a lot of work which directly benefits the Amiga community.
If none of those reasons appeal to you, it also offers upgraded video modes like a Graffiti-compatible mode (used by some games), and also a really sweet 800x600x16 color screenmode which I've used extensively (obviously you should have upgraded chip memory and an accelerator to make best use of this mode).
I can't speak for the compatibility of the other device, but with my Indivisions I've never had any trouble with any of the devices I've hooked up to my Amiga's. That includes TV's, projectors, and modern LCD monitors. In short, it "just works" (TM).
Last, they're firmware upgradable should Jens decide to release any enhancements in the future (make sure you ask for the version 1.10 firmware if you order, I believe that's the latest). Well worth the measly hundred bucks and change most places sell them for! (can you tell I'm a fan?) :lol: