I am a bit surprised. I certainly got good results from my Gaggia Classic when I had it.
It sounds like you have started the long, tortuous and expensive journery to espresso enlightenment.
Do yourself a favour, either shoot yourself now or just get the La Cimbali Junior DT1 now and be done with it.
He he he.
If you did the same exercise with any machine you would probably find quite a bit of variation.
I would like more information on how you measured this. You would need to measure the incoming water using a vary sensitive and rapidly responding thermocouple.