Though I had the radiation in 2018, I was on HT for another two years, and that takes a long time to wear off. So really I'm only a few months post treatment.
My psa is <0.1 but that will almost certainly rise now the HT has worn off. Erections are not very firm, orgasm are dry, but I do have fully functioning nerves which is good news. Bowels are very good, perhaps a little better than pre treatment (radiation apparently causes a bit more mucus to be produced, so no straining when I want to go to the toilet).
Remember my treatment was HDR yours will be LDR and though the principles are the same, you probably can't expect to make a direct comparison between our treatments.
Radiation does not work by killing cancer cells (at least not straight away), it works by disrupting cell division. Cancer cells damaged by radiation will not divide properly, and effectively that kills them, it may be many months after the treatment that they die. Non cancer cells are able to withstand radiation better and also only divide every few years. Some of them will suffer the same fate on division as their cancerous cousins. So the side effects, if any, from the death of these cells will show up many years down the line.
Given the choice between surgery and brachy I would choose brachy. The potential side effects of surgery I would not want.