We are taking steps to improve everything. The new store is slow, and I'm working on implementing better caching to speed it up which is going well (already shaved a lot of time off page loads).
We're also putting a new dedicated database server online today, it's top end and should speed things up nicely.
Thirdly, we're currently being threatened with spam attacks, have suffered bad spates of spam attacks in the past. These drive hundreds of thousands of page views to our site which does slow it down a lot. We're doing what we can to mitigate this (and having some success).
We know it's super important to have it running fast, I'm dedicating all my time to the issue at the moment.