The short version
Gia Lam is a broad eastern growth district where established towns, logistics and new township development meet beyond the Red River. It offers a different scale from inner Hanoi, with more space and more unfinished edges. Choose it only if your work and family life fit the eastern side.
The established town areas have the clearest daily routines. New projects may provide better buildings but depend on roads, gates and planned services. Check what is open now, not what the brochure promises. The river crossing is the decisive part of any central commute.
I would live in Gia Lam for a local eastern life and a larger home. I would not use it as a compromise base for a job in every part of Hanoi.