I have the HF one and love it! I have put a lot of use into it in the last 2 months, and it hasn't had any issues. Also, it's fairly heavy and hasn't broken from multiple drops. I think it's actually a really good tool for the $ (about $35).
I've seen the Dremel version, and it feels like a cheap piece of garbage. I've also looked at the Bosch cordless version, and it's nice. However, reviews have said it drains batteries too quickly.
The Rockwell version is probably what I'll get after I finally destroy my HF unit. The nicer model has VS, and even has a decent dust collection system (not that this tool generates much dust).
I'm sure the original Fein is great, but not for that price!
Here's another thread from another website I go to where this tool is discussed a lot. You'll find some differing opinions than what's on here.
http://www.bt3central.com/showthread.php?t=47502&highlight=multifunction
http://www.bt3central.com/showthread.php?t=43616&highlight=multifunction
http://www.bt3central.com/showthread.php?t=45685&highlight=multifunction
EDIT: I just read the article, and it's obvious the writer has a huge bias.... Also, the writer's incorrect as well. The HF multi-tool went through a change a couple of months ago that updated the spindle to add the indexing pins they thought were missing from the tool. This was because there was apparently a patent dispute about that particular detail, and one version of the tool had the pins omitted. They're on there now, and the review done in December should have had an updated version of the tool by then.
Also, the writer says that the HF tool works well, but the blades stink... He takes the time to note that you can use another tool's blades in the tool, but there's no reason to do that. YET- as the writer states, "It's all about the accessories". So buy better blades and use them in the HF tool, and you have a tool that works well for a fraction of the cost of even the middle-of-the-road oscillating tools... Seems like a no-brainer to me.