Discussion on Oliver Keyes' blog:
http://quominus.org/archives/714
He's coming from the perspective of liaison with newbies. Read the comments.
(I will note that Antoine Musso was right in the previous discussion
that Mantis has a nice, friendly interface. I myself was most
displeased to discover that (a) the code itself is really horrible (b)
it's all but unsupported even to free-software standards.)
- d.