Any 600kg MAUW plane is not going to ride the bumps like a 2400kg plane, common sense really.
Flying in todays economic climate for most pilots is about finding a compromise you can live with. If you can still afford to fly an old Lycsaurus gas guzzler and you are happy with the way it flies then I suggest you stick with it.
If on the other hand you want to try getting more bang for your buck then you will have to make maybe a few slight compromises and putting up with the odd bump in hot weather is one of them..
For my part I built a Sportcruiser and after 15months flying it I love it and certainly wouldn't go back to flying an old stupidly expensive spamcan.
Just quoting comparison numbers though unfortunately does't even begin to tell the full story about any aircraft but if you want numbers there are currently 87 Sportcruisers/Pipersports on the UK register, not bad I think in just over two years since the first kit arrived in the UK and a hell of a lot more than other makes quoted on here.
So whilst it is not a perfect plane (is there one?) I think it is nice plane that I can put into and get out of any 300m strip, gives reasonable performance and handling and has room for lots of bulky baggage and a couple of biggish people. A plus factor as well also has to be that it is arguably the best looking small aircraft around..