I'm a big RPG guy in general. I've probably played around half of all JRPGs that saw an English retail release since the SNES era (inclusive).
Anyway, the speed of battles depends on which particular DQ we are talking about -- DQ8 was slow as molasses.
Resource management is a fair point, it does have a bit more of that than most modern JRPGs (since it's mostly an abandoned concept outside of dungeon crawlers).
Balance, well, balance is something incredibly important to some players of JRPGs and WRPGs alike, but it's not a priority I share. To me, interesting tactical and strategic (character progression / mechanical customization) possibilities are far more important. What good is balance if I end up performing the same rote actions in the vast majority of a game's battle encounters?
And I hate Akira Toriyama's style so that probably doesn't help my enjoyment of DQ
To the bolded, balance can definitely have an impact on the presence of rote, repetitive encounters. If the PvE balance is skewed too far in favor of the player, there is no need to explore additional options within the systems that give that tactical depth. At that point you end up with rote steamroll encounters regardless of the potential tactical depth within the system.