Being a 'lady of leisure' - hope that is the correct term - these days, I would enjoy being asked to run/host any singaround and would enjoy it, although I have run some that have been something of a challenge! I do not think of it as work but would agree that a SAR can be balanced etc. by the way it's run. On the other hand a lot of SARs would run themselves quite happily.
I get annoyed when people that come into SARs late are asked to sing almost as they arrive, when people have been sat in the SAR for 2/3 hours and have still only sang one song - and then when artists come in they are then asked to do 3/4 or sometimes even 5 songs!!!
I've organised a few 'song weekends' over the years and always try to ring the changes in asking people to run sessions as no-one's indispensable!!