I respectfully disagree. It's certainly true that RE6 offers a greater focus on player agency than its forebears, but I felt that this didn't quite carry over to the level design. Indeed, it felt rather claustrophobic; there was an exponential increase in player freedom by removing the shackles of "tank controls", but Capcom still had a tendency to generate enemy encounters within closed spaces, hamfistedly necessitating, say, sprinting and rolling. Put simply, the game's mechanics didn't coalesce for me; it wanted to be an action game but wasn't quite ready to ditch its roots, resulting in a odd hodgepodge.
The environments didn't feel any more compressed compared to something like Gears, with the exception of certain scenarios where it was intentionally claustrophobic such as the ship section in Chris's campaign. Hell, parts of Jake and Chris's campaign given huge, open spaces to move about in. And in any case most third person shooters are hardly an example of open level design. Vanquish and Uncharted(especially with the vertical elements) would be exceptions given most encounters take place in giant arenas of a varying nature.
I do agree that the level design doesn't always support the mechanics as well as it should though, for example the absurd point in Chapter 1(again, a real low point) of Leon's campaign where you can't jump over the table and are forced to go through the metal detector.
I don't think the implication that the game "hamfistedly" makes sprinting pr rolling necessary has much weight. It's simply an option that makes the game's combat and movement feel that much more open to experimentation. At no point does the game lay out enemies in such a way that you must roll or use other similar ground techniques in order to get by. In fact, that was one of my complaints was that the movement options given weren't often required by use of the campaign. The throw back move can be used to avoid enemy attacks but outside of the blades and lasers you're never actually forced to roll or slide about.
Not that I think the campaign is perfect by any means, but that's almost part of the appeal for me after how bland RE5 was. Jake's campaign is a perfect example of how weird and scattershot it can be, with the second and third chapters feeling very divorced mechanically from the rest. It was a positive aspect to me though, as it's something that kept the campaign from growing stale with such a length to it.
In any case, the mechanics on their own really are stellar. The Mercenaries has I said on the last page really feels like a big playground where you can discover just how much depth the combat in the game holds.