I am one who has now experienced both treatments, just as Cheshire Chtis says.
I can tell you that recovery from RP is not at all an easy and pleasant process, men differ but you are likely to suffer significant incontinence for weeks to months, and ED for quite a lot longer. By comparison RT is a doddle, OK you are rather tied down while having daily sessions but the immediate side effects aren't nearly as bad or long lasting (though it had a temporary effect on rectal as well as bladder function). However the accompanying HT definitely affects quality of life, as well as inevitable ED I found I had less energy and put on a bit of flab round my middle, but that should be reversible.
Other things being equal (which they may not be in your case, follow your consultants' advice) the clinical success has been reported as very similar for both. However as I have pointed out in previous threads, that data showing 5- of 10-year cancer-free survival is based on the techniques that were used at least that long ago; things have moved on and my impression is that RT technology is changing faster than RP. On the opposite side is the fact that once your prostate is removed PSA tests are exquisitely sensitive to small bits of residual dividing cancer cells which helps you get salvage treatment quickly, plus the fact that salvage RT following RP is routine where the converse is mostly not possible.
So there isn't a "right" answer, which is why so many of us agonise. I seem to think you said in another thread that your particular pathology seemed to favour RT according to your consultants - in which case I would take their advice.