The real big problem with these decentralized exchanges is liquidity. During volatile times it's hard to find people willing to trade. The spread is very high too, +/- 20% isn't uncommon. For the less popular coins this is only worse. Wait for a day but no one posts a trade within a reasonable spread, and the price change would defeat your expectation.
An exchange without enough liquidity is useless despite its 100+ nice features and technical advantages.
All the differences are really minor. The only big difference is LIQUIDITY and USER POPULARITY. The one with higher LIQUIDITY is always better.