Regarding warm up time and practicalities, the BHSE sounds great after 1 hour, but subtly better after 4 (the PHs seem to need less warm up time than stock, but I wouldn't swear to that).
And it does get quite warm, so all in all it's not the amp to leave on for all the time.
In my experience, most components, SS or tube, subtly benefit from an extended warm up period, so this is not unique to the BHSE.
All else being equal, I'd prefer a SS amp for fit-and-forget peace of mind. But the only serious contender at the time (LL1) was simply not in the same class as the BHSE for me. I've read that the LL2 is better than LL1, but haven't heard it.