Well, that's sort of comforting, although confusing because Chapter 4 and 5 was the only party chat they apparently didn't actually translate at all.
But um... I liked 4 a lot but I have to say that 5 with its monster catching is just a little bit better for me so far. And I dig that 4 got rather nonlinear in chapter 5, although I didn't really like parts of the earlier chapters much, as they were a bit grindy (Torneko and the twins, for instance) and not as... developed (Alena's)? Also I have to say, 5's story is better so far. And I don't really play these games for the story much, but it's got some interesting stuff going on.
Party and character wise, though, DQ4 is really linear, and DQ5, since you catch monsters, is less so. Still a linear skill progression -- that's not something that changed till the 6, 7, and 8 set -- but it makes things feel a bit more varied.
Still say get DQ4 first just cause it's cheaper, though, and 5 should come down in price.