Only just found this so I'll jump in as I'm currently on a 'holiday'.
Initially told to be on Prostap for 3 years but like those above, the side effects became too much. Silly comments such as those above about why would you change, the grass is greener, there's no evidence etc are a clear indicator of not understanding the situation for many men. This isn't just about the inconvenience of some hot flushes. Having serious suicidal thoughts and being told by the doc you are clinically depressed is not to be taken lightly.
So, like the OP the first doc I saw suggested a holiday after 2 years. I asked if this would interfere or become a problem with my long term outlook. He categorically said no. He also referred me to another doc, a consultant, a month later to ask the same question. She said there is no difference in outcomes between intermittent and permanent. She based this on the latest figures at the time - this was July 2017. So my last (for now) Prostap was October 2017. Both docs warned me that the side effects can take up to 12 months to subside and in some cases may be permanent.
It took around 6 months for any changes to be felt and that coincided with a PSA rise from 0.01 to 0.05 after 3 months. Another 3 months on and while still 0.05 no hot flushes, much better sleep patterns and best of all, no suicidal thoughts causing dark days and upsetting my wife with bad thoughts. Libido was returning and around 7-8 months after the last injection, ED had disappeared. However, this was a mixed blessing as the orgasm sensation was quite different and of course, dry. No one ever told me that due to inactivity I would lose 2 inches in length which has never recovered. These improvements have mirrored exactly the PSA rising steadily and went to 0.4 after 3 more months then to 0.8 at the last test.
These figures are considered normal by the doc so remaining on 3 monthly PSA tests. Once it reaches 2.0 will they put me back on a treatment.
So, the question is: would I stay on permanent or opt for intermittent HT? Its a no brainer for me - intermittent.
Hope the OP comes back and tells us what he decided in the end.