You move to the other school and need another 20 hrs to finish your PPL, the extra cost is now a wash.
Interesting perspective B2N2. I was rather hoping that the transition period would be a bit less than 5 hours to cross over to the Tecnam. I did 3/4 circuits, stalls and a glide approach (worked well) during my 30 minute flight in the Tecnam, and was hoping that a few more circuits with an instructor and some PFLs on the way back from up-coming navex's would absorb the transition period somewhat. At least that's what I would hope for if I stay where I am.