The Super Sportster would serve well as a second plane. So much of the decision though depends on the pilot. If your reflexes and eyesight are good enough that a trainer feels annoyingly slow, then one of the speedier planes like a Kaos will probably work out fine for you. If not, an intermediate "sport plane" is a better choice. BTW, the major difference between a sport plane like the Goldberg Tiger or Sig 4 Star vs. a classic pattern plane like the Kaos is the slow speed handling. A sport plane generally has a more stall resistant airfoil and straighter wing to make the stall characteristics more forgiving. An aerobat has some of that dialed back so that snap rolls and spins are easy to do and also are optimized aerodynamically for higher speeds overall. The line between the two is not all that sharp though, as the exact speeds and attitudes at which stalls happen is different for each plane. The most forgiving plane you can get is an Ugly Stick (assuming proper setup and light weight components) with the low wing sport models being a step closer to aerobats, while among the aerobats the Kaos is probably the most forgiving (stall resistant) with the sensitivity to piloting technique going up from there.