Gary,
Still a bit confused on the "porpoising"? Are you saying when you apply power for a go-around while still airborne the plane will porpoise? This is by no means normal for a rookie and would indicate a possible thrust incidence issue. Few questions:
1) do you have any reflex in the elevons?
2) when the plane is trimmed for say half throttle and you apply full power, does the plane tend to climb or descend?

Full power application during a go-around should not have any affect on the airplanes attitude, if it does you have an thrust incidence problem (vectored thrust needs to be adjusted) As with all the Deltas (as Patrick indicated) you must transition in "Slow Flight" before your ready to land, if you can achieve this slow flight configuration you will now be using throttle to control your decent (not elevator) and with practice you can learn to plant the plane anywhere on the runway you wish. Dont rush the landing phase, drop the gear and speed brake, pull back the power till your close to stall speed then come back in with enough power that the plane is flying stable but no more. You will notice a considerable drop in speed and a slight nose up attitude. Take two or three laps in the pattern to get comfortable before committing to the approach (practice this a few mistakes high at first) Once on final, use throttle to control the decent, holding a bit of elevator to keep a slight nose up attitude. Dont use elevator to control the decent, once you drop the nose the speed builds up fast! THROTTLE MANAGEMENT is the key....! As I stated earlier, having flown all three, they all fly and land very similar so your not going to benefit much by changing airframes (at least from one delta to another). It took me roughly 60 to 70 flights before I really learned how to land these Deltas, once you learn the correct way to transition to slow flight your landings will improve greatly Practice, practice, practice BTW, if your coming to FIJR meet next month I would be happy to help .....
Regards,
Todd