my Sig Cap weighs 11# 8 oz dry and with a 160 fx and APC 18x6 it is great. I feel it is fast enough for IMAC, but you have to throttle the engine properly to avoid slowing too much. the 18x8 would be good as well. I want to try a pro zinger 18x6 for better spool up during hovering and I wish they made an 18X8 as well. the APC's are heavy for thier size. I thought I was running about 8600~8700 with a BCM pitts, I get about the same with 10 or 15% nitro.