We kept the old Raymarine T-300 and associated ST7001+ control head. We have two rotary switches which let us choose which autopilot to engage (B&G or Raymarine), and which drive (rotary or linear).
I haven't used the latest Raymarine stuff, so I don't know about pros and cons.
All I can tell you from personal experience and from stuff I have read: don't buy this year's product series. Buy last year's! Generally the stuff that just came out does not have the best software. Whereas if you buy whatever your manufacturer of choice started shipping about 12 months ago, you will be getting stable, reliable software that has been tested and debugged thanks to the other customers who bought the latest and greatest.
But don't buy stuff that came out more than 18 months ago, because then you will only get support for a limited window of time before it is discontinued and support becomes minimal to nonexistent.
SM2K Nr. 350 (2002)
At anchor, Eretria