I haven't had good luck with Asian pears on any rootstock except for OHxF. Any other I have tried has produced weak, poor growth. I tried 3 or 4 trees on P. betulafolia and all died within about 3 years.

also my soil ph is 5.5 is this too low for pears? i have read that they like between 6.0-6.5

I planted in Feb 2010 a 20'th century, Atago, Hosui, Chojuro, Shinko, Tsu Li, & Ya Li, all on calleryana. I also planted some keiffers, garfber, monterrey, moonglow, green jade, etc, also on Callery; as well as some other pears on OHF97, Quince, & Pear

I've been summer pruning to 6 ft, so I cant say exactly what growth would have been. All my pears grew 3-6 ft in 2010; & then slowed down in 2011, though with the record heat & draught, I was happy to keep everything alive.

The Ya Li died the first year, I dont know why. The Chojuro died of fire blight, I replaced it with another Chojuro, which also died of fire blight.

The 20'th Century, Atago, & Tsu Li look great. The Hosui & Shinko are looking kinda puny but are ok.

Texas A&M recommends Callery for Asian pears, should be ok....i hope.

I know 3 years isnt really enought to answer your question. Hopefully Scaper see's this thread, I believe he has lots of experience with asian pears & calleryana.