For the record, I have no experience with the AEV Procal so I have no direct comparison. I ended up purchasing the Flashcal from Quadratec for $144 shipped. Only reason for me was the screen scroll vs. the dip switches, and the screen scroll menu is idiot proof, I proved it last night.
Yes, you do need to spend about 10 minutes checking for updates online before plugging it in, painless. Once you plug it in within minutes depending how in depth you want to get, you are done. I did before and after with GPS, got spot on where I was 2-3 mph off. Shift points, well in my head they seem a bit more crisp again but I just plunked down $144 so I'm sure I was looking for that improvement. I need more seat time to really know if it made a difference there. All the other options I'll be playing with down the line.
All in all, I would give the Flashcal a thumbs up. I'm sure if I bought the Procal I would say the same thing, for the same amount of jack it just "looks like" you get more from the Flashcal.