I haven't played a single game with engine (there are a lot of others who play

), but ran 4 testsuites and WOW. It's much better in tactics and endings than Naum4. Solutions for 4.1 (in brackets 4):
tactics 1 (ECM subset) - 74 (68)
tactics 2 (Arasan subset) - 102 (95)
EET (endings) - 61 (55)
Endings 2 - 79! (63)
Jouni