Generally, the problem with plastics is too many flutes and too much speed resulting in melting from rubbing instead of cutting. The answer is single flute bits and slow RPM with higher feed rates. But once you get your bit, speed and feed right it cuts like butter.
I would love to know some of your speeds and feeds for cutting acrylic. I did make a couple of pieces from it recently using a new, sharp, single flute cutter specifically designed for rigid plastics but it was terrifying. The parts came out fine but I got so much vibration/chatter and uplifting of the part I thought to myself I'm never doing that again at the time. I kept experimenting with RPMs but the speeds were set based on some values I calculated for that material and that cutter. I got good clean chips and no melting but it was still pretty scary.