I've played since 1978 (yep, I'm old) and DM'd since 79 (yep, really, really old). This is the first edition of the game in decades that has absolutely captured my imagination. My few concerns (no spell list by school, no notes in the list for concentration or ritual, the "non-offensive" art is sometimes rather odd or bland, some rules are vague (of course you add Shield or Cover to AC when using Barkskin. Seems like a simple sentence to add
) are exceptionally minor. I have had an absolute blast just rolling up characters with all of the options pre-made in the apparently simple rules.
This is not the end-all-be-all rule-set. A 6E will come along in time. But, for now, it is an amazing edition.
Overall, I would score the PHB a 4.5/5.0. The MM at 4.8/5.0. The DMG at 4.5/5.0.
I hope, as mentioned above, that they avoid over splat-book-ing us
Only splat books I would like to see are those that serve an obvious purpose (i.e., psionics).
Having played basic, 1E, 2E, 3E, 3.5E, 4E, loads of Pathfinder, I can say that this edition will comfortably replace all at my table.