Hi as a Gold Star 650 owner and a Club Member I would also appreciate a specific area about these models.
On the suspension front I fitted some lovely Hagon rear shocks with the black shrouds to match my bike, not only do they look much better, the bike feels much better. The damping is much improved and gives a smoother ride. Also, I then fitted the TEC progressive forks springs which again really improve the ride and feel of the bike. So I would recommend the upgrades.
I also went up 1 tooth on the front sprocket which keeps the motor more in the 'sweet spot of revs' 3000 - 5000 rpm at normal riding speeds (there is no point going over 5000 rpm just let the torque of the engine do the work) So, this makes just over 60 mph around 4000 rpm and if you need to overtake then 5000 rpm gets you to around 83 mph, which is great on a B- road.
I hope this helps.