RE: Difference between IMAC and Pattern
I've flown both Pattern and IMAC at the lower levels. To me, the flying and contests in lower classes are so similar it's hard to tell them apart except for a slight format difference. The big difference to me is that while you can fly smaller planes in IMAC they are not the norm and you may feel the need to have a large plane to fit in. In pattern it's fairly common to see people flying planes as small as .40 size and very common to see planes .90 to 1.20 size. That said, IMAC contests seem to be more common. If you have contests for each discipline in your area go to one of each and see what you think. I'm certain you'll have a good time no matter which you choose, assuming you decide to choose. Some people fly both regularly.