Nomis, I've been through much the same path ... age 78 now, G9, RT and HT in the form of Zoladex for 21 months.
I noticed a significant improvement in QoL starting from the time when the effects of the Z were wearing off. Testosterone didn't come back till about a year later and that's been welcome. During the HT I gained about 9 kg, which I've now shed. I exercised to the best of my ability during the Z phase and it was always frustrating, though now the testosterone is back it's possible to push things along a bit and get results in terms of fitness. 5 km park runs are helping and any form of external reason for getting active is good during or after the Z treatment. I did a couple of prostate cancer fund raiser targeted efforts, where the goal was to run 70km in a month.
All up, the answer to your question was yes for me.
Bet you can't wait Derek.
Jules