Mathematica 7 compares to other languages

[budden]

Mathematica is a great language, but:
1. it is too slow
2. It is often hard to read
3. It gives sence to every keystroke. You press escape by occasion and
it goes in a code as a new
symbol, w/o error. Nasty.
3. I know 5-th version. It does not allow to track the source as SLIME
does. This feature as absolutely
necessary for serious development

So, in fact, Mathematica do not scale well IMO.