Top left in Opera browser, click on the Opera logo thing, then in the menu at the bottom go to About Opera, it shows where the Profile Folder is. Most commonly on Win7/8 it will be Users > Home > AppData > Roaming > Opera Software > Opera Stable but that is default, it could be somewhere else.
That does seem to speed up things a bit but (having the same problem) it does feel a lot slower than the old Opera on the whole but I never kept time so it may just be subjective impression.