I helped friend with project for university. It had 4 counters(<2Hz, 50% duty) and 4 timers, 16x2 LCD and it was problem to fit all that code in microbasic on pic16f877. Simple code, I thing PBP version had less than 4K.
It has a lot of futures built in. Also TCP/IP works out of box on dev board, but again lot of overhead code. I have done similar things in PBP, with much less code space.
I thing that they work a lot on supported futures, so it is really easy to implement lot of things.
I work a lot with low power stuff(battery operated sensors, etc) and small code that PBP generate is almost always enough to achieve product life as long as battery shelf life. If not, then I do it in ASM.
So even if I have powered stuff, I'll do it in PBP because I use to it, and it is good enough.
MicroBasic support string, floating point by default. But I can use simple include for PBP to get just that. Also string functions are really easy to implement using arrays.
So I don't see benefit by buying MicroBasic. That is my opinion...