I had that phone. The keypad was indeed unbearable. Right after I bought it, my friends started getting Nokia 6600. It was a major improvement in every way.

3650's camera was 640x480 and had a noticeable delay after taking a photo. It had acceptable shutter speed but if the subject was moving, it would be blurry. 6600 was a lot better. I think it might have been slightly higher resolution as well. 3650's videos were really low frame rate and barely acceptable. 6600 had better video but still not great. At least usable at that time.

I really hated 3650's keypad. Siemens SX1 also was memorable with its weird keypad. [0]

[0] - https://sm.pcmag.com/pcmag_uk/review/s/siemens-sx/siemens-sx...