There is one thing that really makes me unhappy with HTB and I think it's the only one. Randomization in retired machines pool is quite poor feature IMO. I know there is a voting system, but I can only vote for 3 machines, some of 20 limit is being picked by other people and some is random.
Surely, HTB is a learning place for me and most likely others and I can't choose what I can try and learn since all machines offer different things to train(that's awesome). That's like you pay for entering a library but not allowed to select the books you can read.
For the records, I have Blue in my top 20 retired machines list which I have done several months ago and have no interest in doing again.
Hopefully there can be a solution to this issue, for example I can access all machines(might not be a good idea cuz of costs) or a limit of 20 machines per week which you touch.