US stocks bought at Xetra?

Hi all, Belgian brokers normally charge a currency conversion fee if a user buys US or other non EU stock. Some US or other non EU stocks are also listed in, for instance, Xetra, in euro. Is there any drawback in buying such stocks from Xetra rather than say Nasdaq in the original currency, apart from liquidity? Is it worth to buy in xetra to spare the conversion fee?