I started on Durandal myself and my main issue were queues. Queues on a JP server take forever if you don't select the option to party with Japanese and if you do, while it's possible to get along with the auto-translate it can be a bit frustrating to plan out strategy if you need to with limited communication and I don't like inconveniencing the Japanese players by doing so.

Honestly, I just rerolled on a standard NA server months ago when all the people I started on Durandal with vanished so now I don't have much of a reason to even play this character anymore.

There's also the pings, JP servers are actually located in Japan while the NA servers are in Vancouver or somewhere in Canada so I feel like my latency's better on the NA server.