Since I was invited to join the signature campaign, I did a small test (not on Mobile) to exchange some LTC to XMR. What I really like, is the lack of Cloudflare. The clearnet site just loads normally in Tor browser, and that's something mosts sites can't do anymore nowadays.
What surprised me, is there is no fixed "fee per transaction". It looks like the 1% or 0.5% fee is really everything, which matters a lot on small transactions. The minimum amount is 0.0001BTC, and much lower in value for altcoins. I haven't tried a large amount, as it was only for testing and I don't really need to exchange coins at the moment.
So far, I'm not disappointed and bookmarked the .onion site (on my desktop). I kinda expect people to complain about the limited choices of altcoins though.