I recently got it, and I think it'll be a "grower" for sure. The production is really weak and detracts from the power of the songs. The vocals have suffered a little, but I don't find it distracting as some of the others here have mentioned. I do think that I'll grow to like it a lot more with a few more listens, because there's definitely some solid work on the album.
However, I am glad that they cut down on the song lengths a bit, since "Gates of Fire" went far too overboard in that aspect. The first three songs of GoF are phenomenal, but as soon as it hits "The Fall of Iliam," the whole album turns into a really tedious and boring affair. Just for the record, this opinion is coming from someone who considers "Spiral Castle" as the strongest of the "new" MR releases, so make of that what you will.
Anyway, even though Manilla Road will most likely never top the glory of the early releases, I am glad Mark the Shark still out there making solid albums.