Dick Allen's Stark Shark has won every VRCS Class II meet he's entered in Florida and NY, to my memory. Dick designed it in the 60's and at age 75+ he can still out-fly many a younger man.

I scratch built and competed with an Aristo Cat earlier this decade, very good flying design though I would agree the II Perfection is probably the most developed contest model ever designed for Class II.

My 'Cat had an OS 40SF, if I build another I would look for a bit more power...maybe a K&B 61 or OS 60FP.