Hi Mike, Sector ETFs are well suited for AIM and I believe Tom has AIMed a portfolio of sector ETFs. The only sector ETFs I own are IYE (energy) and IYZ (telecommunications)and KRE (bank) and the latter has not done much. These have very long wavelengths of several years and do drop by 50% or more, so you have to have a long time horizon and strong stomach.
I tend to follow portfolio advice that the core should be diversified over stocks, bonds, REITs , commodities and cash, and my stock ETFs are mainly style ETFs like SCHA SCHE SCHC and SCHX, since I have a Schwab account I get commission free trades and the're very low cost. After the core you can assign a small portion for something more volatile and interesting like a stock or two.
You do have to be very careful with AIM when you use it on individual stocks and other specialized investments that you don't sink money into a losing stock, as on the way down AIM behaves like dollar cost averaging on steroids and can lose a lot money.