Recently, I've been thinking about the 4*40 kit, as there's one sitting at my LHS. I kinda skipped over that step and went straight to a H9 Funtana after the LT-40. I've since assembled and flown my Brightstar, but due to its flat bottom wing and dihedral, it doesn't behave any better than the LT-40 on aerobatics...

In regard to the engine... I first flew the LT on an Irvine .39 which worked very well. I then swapped it for an OS 46FX (to break it in) which gave no real improvement in flying characteristics but does make the nose drop more when power is removed even though I moved the battery back. I have the 46LA on the Brightstar. It suits the Brightstar well, but I don't anticipate using it for anything else as it rattles and makes considerably less power than the Irvine .39. The Irvine makes almost as much power as the 46FX.

In short, if I build a 4*40 I'll put my Irvine .39 in it. Its light for a BB engine as its actually a 30 size with 40 size power.....

As for the 4*60, that's a whole new ball game. I'd consider the ARF maybe against the Tiger 60, but if I were to go to the trouble of building the kit I'd probably get the Venture instead....