The BHK250 (and 300 monoblocks) is an excellent product and a good choice for “my last amp”. I’m thinking along those lines, but then, I don’t know how much longer I’ll be using mine so a replacement many years in the future is a possibility. And, yes, shipping a 94 pound amp back is not fun, been there, done that.
As far as design issues, the only one I am aware of is the original binding posts were substandard and were replaced (hence my shipping it back). This only impacted the initial production run and I’m pretty sure it was corrected within six months of release. I’ve had my amp for 2-1/2 years without any serious issue, I did have one fuse blow, but that was a simple thing to replace. Fuse blowing is not a problem unless it happens repeatedly. As for overheating, most of the forum posts are from folks who are not sure what constitutes “too hot”. From what I recall no amps were actually diagnosed as overheating, at least that had adequate ventilation. If I am wrong, hopefully some one will correct me. Finally, I’m not familiar with the “clicking” issue, at least with it being a fault. There is a relay in the unit and it does click when turning the unit on from standby, this is not a problem. I did have some noises early on that sounded like “clicks”, but they were expansion sounds. By that I mean the heat sinks expand when they get warm. As the heat sinks expand they can make a tick sound as the metal moves relative to whatever it is attached to. These sounds disappeared after a period of time as the mating parts that were moving relaxed. This is normal.
Now having said all that and you are still not convinced, you can consider the Stellar series amps. From what I have read they are quite good, cost less, and weigh less too. Good luck with the quest!