Although I crunch F@H for DSL I have found the client to be the easiest to set up and the best at not interfering with other processes.
The release of CPU cycles to allow other programs to run is perfect unlike CPND and SETI on my machine, the only problem being the time limit issue on older machines and 24/7 running on a P400 will just scrap inside the limit.
At the mo I have been toying with running SETI, CPND AND F@H on my 2200+ at the same time with reasonable results, although I have found that I still gravitate back to SETI as the WU's are that much shorter. On my machine one frame takes between 5 & 25 mins depending on the protein and still a whole unit can take a couple of days. Compare that to my P400 that took 10 days of 24/7 running to complete one WU.
Sorry to say I will not be joining but I hope your recruitment drive goes well.