I'm on the Japanese servers of Pazudora, though I just started a couple of days ago.
There's an event running where you can get this Golden King Dragon once each day... That's going to be helpful for me, since each one gives 50000 EXP... Wow.
That's only on the HK/Taiwan version which shares the servers with Japanese version, since it's for celebrating PAD being voted the best mobile game on a Taiwan forum.
The main attraction for most people would be the stone you get from that dungeon everyday though.
You would have had missed out on PADW delay compensations on Japan version if you started playing earlier on the HK/Taiwan ver, but that one already ended so it doesn't matter.
If you decide to continue on the HK/Taiwan version, you may miss out some of the collab dungeons due to copyrights (e.g. HK/Taiwan didn't get DBZ, etc, instead they'd revive dungeons like questionnaire dungeons, vampire dungeons which are very helpful for newcomers), but I believe transferring account between HK/Taiwan and Japanese version is incredibly easy so you can switch around to get the best of both worlds. (I haven't done it before so I'm not sure though.)
I play on the Jap servers too and my id is 175 462 292