Classics are still a blast, as far as hobby enjoyment use goes. They can pretty much do everything that Pegasos II or AmigaOne can do, however slower, but as far as actual "useability" goes, they are pretty much on par (e.g. lack of up to date software).
Upgrading your system to a PCI busboard would surely bring you some performance improvement, however since you already have a CVPPC video card, it probably wouldn't be worth the upgrade, unless you are looking for an ethernet and sound card solution. In that case, I would go for it.
