On the Linux client (64 bit), the "minimize on close" will still minimize to tray (causing X server hang after a short while by spawning multiple tray icons).
But, the priority of the threads all seem to be "nice" properly I think. The ones using all the CPU time are nice to 19, so the others that are 0 and 2 aren't using any CPU time so the system seems to be responsive.
[knightmb@KnightMB ~]$ ps -eflL | grep bitcoin
0 S knightmb 13676 13591 13676 0 9 80 0 - 113704 poll_s 14:52 pts/1 00:00:02 ./bitcoin
1 S knightmb 13676 13591 13681 0 9 80 0 - 113704 hrtime 14:52 pts/1 00:00:00 ./bitcoin
1 S knightmb 13676 13591 13682 0 9 80 0 - 113704 hrtime 14:52 pts/1 00:00:00 ./bitcoin
1 S knightmb 13676 13591 13683 0 9 80 0 - 113704 hrtime 14:52 pts/1 00:00:00 ./bitcoin
1 S knightmb 13676 13591 13685 0 9 80 0 - 113704 hrtime 14:52 pts/1 00:00:00 ./bitcoin
1 S knightmb 13676 13591 13686 0 9 80 0 - 113704 hrtime 14:52 pts/1 00:00:00 ./bitcoin
1 S knightmb 13676 13591 13687 0 9 82 2 - 113704 hrtime 14:52 pts/1 00:00:00 ./bitcoin
1 R knightmb 13676 13591 13689 70 9 99 19 - 113704 - 14:52 pts/1 00:09:34 ./bitcoin
1 R knightmb 13676 13591 13714 71 9 99 19 - 113704 - 14:53 pts/1 00:09:39 ./bitcoin
1 R knightmb 13676 13591 13924 72 9 99 19 - 113704 - 14:53 pts/1 00:08:19 ./bitcoin
1 R knightmb 13676 13591 13314 73 9 99 19 - 113704 - 14:53 pts/1 00:08:19 ./bitcoin
1 R knightmb 13676 13591 13114 74 9 99 19 - 113704 - 14:53 pts/1 00:08:19 ./bitcoin
1 R knightmb 13676 13591 13984 75 9 99 19 - 113704 - 14:53 pts/1 00:09:19 ./bitcoin
1 R knightmb 13676 13591 13214 76 9 99 19 - 113704 - 14:53 pts/1 00:09:09 ./bitcoin
1 R knightmb 13676 13591 13917 77 9 99 19 - 113704 - 14:53 pts/1 00:08:12 ./bitcoin
1 R knightmb 13676 13591 13919 78 9 99 19 - 113704 - 14:53 pts/1 00:08:39 ./bitcoin
1 R knightmb 13676 13591 13934 79 9 99 19 - 113704 - 14:53 pts/1 00:08:51 ./bitcoin
1 R knightmb 13676 13591 13114 80 9 99 19 - 113704 - 14:53 pts/1 00:08:39 ./bitcoin
1 R knightmb 13676 13591 13624 81 9 99 19 - 113704 - 14:53 pts/1 00:09:11 ./bitcoin
1 R knightmb 13676 13591 13224 82 9 99 19 - 113704 - 14:53 pts/1 00:08:39 ./bitcoin
1 R knightmb 13676 13591 13374 83 9 99 19 - 113704 - 14:53 pts/1 00:08:55 ./bitcoin
1 R knightmb 13676 13591 13261 84 9 99 19 - 113704 - 14:53 pts/1 00:09:43 ./bitcoin
1 R knightmb 13676 13591 13171 85 9 99 19 - 113704 - 14:53 pts/1 00:08:55 ./bitcoin
1 R knightmb 13676 13591 13741 86 9 99 19 - 113704 - 14:53 pts/1 00:08:23 ./bitcoin
1 R knightmb 13676 13591 13371 87 9 99 19 - 113704 - 14:53 pts/1 00:09:42 ./bitcoin
1 R knightmb 13676 13591 13690 88 9 99 19 - 113704 - 14:53 pts/1 00:08:39 ./bitcoin
1 R knightmb 13676 13591 13234 89 9 99 19 - 113704 - 14:53 pts/1 00:08:33 ./bitcoin
1 R knightmb 13676 13591 13703 90 9 99 19 - 113704 - 14:53 pts/1 00:08:38 ./bitcoin
1 R knightmb 13676 13591 13991 91 9 99 19 - 113704 - 14:53 pts/1 00:08:39 ./bitcoin
I'm not exactly sure what the "Start BitCoin on window system startup" is suppose to do?
On library errors, you get a
/usr/lib/libstdc++.so.6 'GLIBCXX_3.4.11' not found on older linux clients (one was only a year old). I checked the file, it's just linked to libstdc++.so.10 but I don't know if that's a high enough version or not.