Compiler,
I think the recommendations vary by doc and probably by patient too. My doc had me walking ONLY for a month after surgery, but NO restrictions after that (cardio or weights). Same doc did same surgery on a neighbor and had him walking only for 2 months and no weights, golf, skiing, etc for 3-4 mos can't remember (although he was a bit older, 62 I think).
I was back on weights, free and machines, after 6 wks (waited an extra 2 wks) and am back to same weights/reps as before surgery now almost 4 mos out. I did start very light though but built up surprisingly quickly. On the treadmill, I started building in 1-2 minute jogging intervals 3X during a 45 min session. I'm up to three 5 min jogs at 6-7mph in a 45 min 4 mph stiff uphill (5-10%) walk. I'm working out 6 days/wk (4 cardio, 2 weights). Feeling great. I'm a bit of a fanatic (was before PCa too), but makes me feel like I'm doing my part to beat the beast!
Obviously make sure with your doc, whatever you do, but I think the keys are to 1) start slow, and 2) let your body tell you how much and how fast increases should come.
God luck!
Ralph