Some pretty good advice above. Trying to jump to too much airplane too early will slow your learning. But the two designs you mentioned are pretty good designs for perhaps the third model or second if you have a good instructor. A good instructor keeps pushing you well past the point where you have soloed, for a year or two in more advanced models.

But before you give up on the LT-40, it's time for you to learn what it can really do when set up for advanced flying. This means moving the balance point to the rear of the CG range and working up to more control throw. When pushed to it's performance setup, the LT-40 will do inside and outside loops, fly inverted all day long, spin and do snap rolls. Once you can do these things and other combinations, you will be ready for the stik or Pulse.