I’ve definitely run into that quality drop when saving my own clips through the app. If you're looking to keep that original crispness without the watermarks, you should check out this
site.
I’ve been using it lately because it doesn't compress the files as much as other tools I've tried. Plus, it’s all browser-based, so you don't have to deal with any extra software installs or accounts. I usually grab my videos in HD or high-bitrate MP3s (like 256k) there, and it works perfectly for keeping a clean archive of your own content.