I was looking in to C compilers last year, and got some great feedback from a guy whose job requires him to be familiar with just about every pic compiler. (His feedback was offline, because he could not post his opinions public for the same reason he knows about all of the compilers. I am going to respect his anonymity.) Anyway, his advice regarding Mikroe and their compilers was to avoid them, for a variety of reasons. (Which mostly boiled down to "you get what you pay for.")

I own PBP, and find it a great compiler for people wanting to step up from Stamps. I mostly use Proton Basic (PDS), however, because it compiles much more compactly (about 20%) and runs faster. It's only $165, and even comes with a simulator that allows you to step through your code and debug much faster. The sim is limited to a couple chips and a couple development board models, but that allows you to test routines without messing with hardware. (I purchased the full sim so I can create just about any circuit I can think of--but that is not cheap.)

For the most part, you get what you pay for in compilers. Comparing PBP to PDS, they are very similar (they both used BS2 as a base), but PDS is more powerful. The same guy mentioned above said PDS "is as close to coding in asm as it gets for any pic compiler." The biggest difference is that PBP is a little more oriented (better oriented?) towards beginners because it has fewer features to trip you up. PDS has a larger command set, and built in interrupt context saving. The parser is better with PBP, so you can string together many math equations on one line with lots of parentheses to make it readable...but if you separate them out and use PDS, your code will be a LOT smaller.