It will be a huge step down in power. Whether you are OK with that only you can answer. You may be good with at first but then miss the power later on. Get a long test ride, it's the only way you can tell. The good thing is that it will slow you down, whilst it can do over a ton, it takes a good while to get there by comparison, and it is a lot happier when kept below 80-90.
The 650 is very good value. It's the swiss army knife of the biking world. It does everything reasonably competently.
The bad...
Well the suspension is not very good. Limited adjustment and fairly soft as standard. You can add an after market fork brace to help stabilise the front. You can add stiffer fork springs if you are on the lardy side, and you can always replace the rear shock.
It will suffer from corrosion around the water pump housing, so keep on top of the cleaning there. ACF50 spray is your friend if you are using it in all weathers.
You may or may not suffer from buffeting with the stock screen, many do and replace it with various after market screens and adjustable screen brackets.
The lights are not relay operated, so the full load goes through the switch gear, this can cause issues with the lights on older bikes but you should be OK for a good number of years before that happens. An aftermarket relay solution is available to prevent this happening. Having said that, the lights are very good.
The brakes are a bit naff. Changing to some HH EBC brake pads up front will help, but you will never have sports bike performing brakes.
The stock tyres are pretty poor (some people are OK with them). The only time I had the ABS cutting in under hard braking was with the stock tyres on bumpy roads.
I don't want you to think it is all bad, I'm just trying to prepare you, it is a very good bike, and I can't think of anything better at its price point.