Older versions at the above link do not have to be unzipped. But even if they did, free zip utilities are widely available. Windows has one natively: simply right-click a zip file and EXTRACT ALL.
You are a registered user, so upgrades are free for up to six months. After that, your purchase will continue to fully function but a fee will be required in order to register the latest.
Contrary to your experience, no slowdown has been noted here. Speed and efficiency are regularly improved. Share your 'slow' project and folks will check it out.
http://nch.invisionzone.com/topic/23659-tips-for-getting-help-on-this-forum/