I just installed a SPP6E in my Coleman AC this past weekend. My unit already had a start capacitor in addition to the run capacitor but the factory starting unit was really small. I could always start my unit with my honda genset but it really bogged down before, not it starts easily and doesn't bog down. It is a 20 min upgrade and well worth it in my opinion. Also, I would recommend the 6 vs the 8.
1998 Jayco Eagle 302FK (Honda EU3000is)
2016 GMC Sierra Denali 3500HD 4x4 Duramax/Allison