Sky: Nix the Cub. Its squirrely on the ground and a bit** in a cross wind. Every time you turn into the wind (as on final approach) it will tend to rise up. The flat bottom Clark Y airfoil balloons in the wind. The Cub is a ship intended for a calm day.

I don't know too many arf trainers. I agree a 60 sized one will fly better than a 40 sized one.
As I mentioned in the previous reply, the $ spent on a trainer are not wasted $. You can get alot of usage out of it. You can use it as a trainer for the kids, a radio test ship or at club fun flys. I use my trusty (& musty) Swizzle Stick for club fun flys. I also do a maneuver I call the spin & puke. I have enlarged the size of the ailerons and the rudder by 50%. I climb up to the club ceiling at the field (300') and throw it into a spin. The idea is to get in as many spins before you are forced to recover. [>:]I've come mighty close on several occasions.[X(]
By the way that Swizzle Stick is over 15 years old and has many-many (thousands?) flights on it. I have recovered it twice. I'd say I have gotten very good value out of it, wouldn't you?
I tend to be conservative in my approach to flying and that extends to the giving of advice. I do not think that one should advance to the next level until one has gotten all benefit from the current subject. Go with the 60 size trainer. Fly the ship until it is second nature to you and your reactions are automatic. Then you can increase the throws (slowly, in stages) and hone your flying skills. For want of a better phraseology, I will say develope your "feel" for what the plane is doing. This way you build new skills upon a solid foundation of experience.
By the way, my first 2 flying sessions out of the winter break are with my Bernie LW. Basically its a straight wing Kaos, 65"wingspan, Tigre .75. Once I work off the winter pilot rust I roll out the Lady, or this year my Kange CAP 232. I'll put in another couple flying sessions and then roll out my 75" WW1 Halberstadt Biplane.
The point is, I do it in stages. I proceed when I am ready and feel comfortable to do so. Could I do it diffrently, sure, but I said I was conservative and I absolutely HATE to repair my planes.[:@]
Well, that certainly was a long winded opinion.
Happy landings, Tony.