I've played Caster of Magic for a bit. Approach it the same way you approach MoM and you'll be really hurtin'. Normally Warlocks can trounce 99% of random dungeons, but I ran into a lot of setups that really caused problems. Nightblades are much more of a threat than they used to be, for example.
The 1.5 patch is just a patch, it doesn't aim to improve the game outside of making it play they way it should, bug fixes, etc. Caster of Magic aims to make the game better, while still playing/feeling like MoM.
I disagree, I think that Caster of Magic is a different game that utilizes the Master of Magic graphics and ruleset. Tons of things have been changed and the game plays completely differently.