IMHO the blame for that lies with the software, not the hardware. Android is basically the realisation of the original Java OS, but on hardware fast enough that its performance has become "acceptable" - most of the time.
As for the other features; Bluetooth, WiFi, accelerometer (and compass/magnetometer), SD, dual-SIM, and removable battery are pretty much standard on every generic Chinese phone now since they're based on reference designs that have all those components (they cost almost nothing - it would probably take more work to remove them and customise the HW/SW - and it's yet another feature point they can list.)
I'd consider such a "full-featured" phone "flagship", but what the term appears to mean today is just a fast CPU, big screen, and pretty looks, with the other features appearing and disappearing seemingly randomly.
This is what bothers me. I suspect it's not random, it's market segmentation. So ok, a vendor may think that some consumers value feature X, Y, and Z, while others value featues X, Q and V. But one thing that is missing from all offerings is a phone that has them all. This is the phone that I would like to buy, even if it was significantly more expensive than the rest. But I can't, because it's not there.
(Or I haven't found it yet. If anyone knows of such device, I'd be grateful for a pointer.)
The animations are just too slow and annoying for me to get used to. There needs to be a way to turn them off. The phone wasn't laggy. It's just the animations that got on my nerves.