Cliffnotes: If you want a new phone right now, get the D3. Otherwise hold out for something later.
A rooted D3 (someone will get into it eventually...) will run you for a couple years or atleast until those 8 or 50 processors are out.
I don't have any of the issues with my D1 that you had. It rarely slows down and I usually only run at 900Mhz. If I run it at 1.1Ghz, forget about it, haha.
D1s were never meant to run Gingerbread, yet both my D1s ran it flawlessly.
D3s are made for everything, they are the latest and greatest. Apps haven't even caught up to it.
I'm holding out for quad-core and sticking with my D1 for a while. The D3 and the Bionic are the only phones credible to replace the D1 right now. Everything else is about equal and lesser quality then the D1 right now.
PS: The Droid 1 hasn't been out for 3+ years.