I've had the gen1 and gen2, I certainly wouldn't describe them as slow, so something is making your bike slow. You say it's a bit tired, do you know when it was last serviced or what was done? First thing I'd say is check the air filter and check there are no blockages in the fuel lines and give the carbs a clean. I'd start there and see if there's any improvement. As for the handling they can be a bit twitchy if the suspension is not set up for your weight. I found my gen2 was like that when I got it, the previous owner had set the rebound to its maximum position so check that out too.
These are the first steps I would take before more indepth investigation