my two cents: I currently use a three year old 2.4 ghz MBP with 8 gig ram and an ssd drive. This setup allows me to work quite smoothly in the adobe family of programs.
I do suffer with compression time for vimeo files and so if I was to upgrade it would simply be a newer MBP with more ram and a faster processor.
I would advocate for staying with a MBP. I know there are some great setups on pc machines and some that are more powerful than a maxed out MBP as well as cheaper priced. However, the main drawback to even a souped up pc is that you’d be stuck working on the windows platform and for that reason alone I’d argue for staying with a MBP.
as a freelancer i’ve worked extensively on both platfoms and when it comes to ease of use the MBP wins easily.