Sorry to butt in but I just wanted to say that I totally agree with you when it comes to hypotonia. My daughter has global hypotonia and it feels like every milestone is a hard fought battle.
She is 20 months and just figured out how to crawl a month ago. What makes me laugh (sometimes cry) are the people who see me helping her stand and they say "oh look, she'll be walking any day now." Um, no. She won't. I wish she would but like everything else it will take time.
I will say that every time my daughter learns something new I feel this huge sense of pride and accomplishment for her (and me). And PT (with consistent work at home) has helped a lot.