The 620 is not a bad model, though, and was a lot more expensive than its 650 sibling when new. It features a 1/4000 top speed instead of 1/2000 and also a 1/250 flash sync. Also multiple exposure capability was introduced, which was absent from the 650. Autofocus and frame rate were both improved for the EOS630 AKA EOS600, although, strangely, the shutter reverted back to 1/2000 max and 1/125 sync speeds.I bought a used eos 650 and replaced it with a620 less than 75 us total gave them both to nephew telling him to sell the 650 to by what ever he could.I thought the auto focus was to slow in low light with a2.8 seemed to hunt to much and the battery life was to short.Replacement was an EOS1 with bp e1 which Istill have and now a EOS1V with bp grip .I like using aa batterys much better. I did have an Elan 7 with bpack which also went to nephew with same instructions sell 620🙂
The early EOS models are great value for money today and with a decent Speedlite such as the 430EZ or 540EZ offer a lot of versatility for very little money. As long as the shutters are clean and goo free, the only other issue may be rapid battery discharge from the LCD illumination circuit (from memory). I greatly prefer a manual focus SLR (usually something old and German) but, whenever I need autofocus or no-brainer perfect indoor flash fill my 630 or EOSRT are the first cameras I reach for.
Canon's own online museum site has a great potted history of each model, original prices (usually in Yen), and specifications, brochures etc.
Regards,
Brett