It is normal that new software versions are "heavier" than previous versions and demand more from the hardware, not only Vue but everything in general. Look at Microsoft software, for example.

This topic has been already discussed in this forum and I also made some tests. Indeed it's true but it's only noticeable if you're on a medium system. For example, I have 8GB, Vista 64 bits, and the additional RAM that Vue 7 needs is not noticeable. Instead of having 4GB RAM free, I have 3GB free. Not relevant. But if you have 2GB total, that overhead becomes very relevant. So, my suggestion would be that you need to upgrade your system. :-)

Regarding slowliness, that probably has to do with the RAM problem. In my system, Vue7 is faster than Vue6.