Isn't dosemu only for Linux? I don't use Linux, so I don't use dosemu :p
If you read my early posts on VOGONS, you'll see that DOSBox was a hard sell for me, but now I really like it. A lot. I also respect Qbix and Harekiet's vision and dedication (although I think their views on the possible uses and development avenues are a bit more conservative than mine) and above all I am impressed with the DOSBox community. VOGONS (the regulars, the mods, and of course our Fearless Leader, Snover) is great (I can only think of one person who I've butted heads with in the last few months), as are the mad scientist crew of freelance devs and the dedicated, patch-hungry CVS build releasers. I doubt there are many open source projects that have such dedicated, active communities.
On the subject of VOGONS: Someone ought to mention this forum in the Wikipedia article on Vogons.
Edit: Read a little of the linked thread. I feel I should address their criticisms on DOSBox's higher requirements by emphasizing the fact that it's probably largely due to Qbix & Harekiet's forward-thinking approach of making it cross-platform so that it will continue to run on future platforms. Dosemu and QEMU are probably going to fall by the wayside eventually (like when x86 finally goes out of style), but DOSBox will still be around in some form or another as long as there are people interested in playing old DOS games.