Hey Luis -
Had a good look at both, and while I don't you are totally there yet I don't think you are really in all that bad shape either. I personally think you are in much better shape overall with the MW version but there is, IMO, still some work you could do. Here are my thoughts on it:
I prefer the wood in the second, but I think both could use more variation. They both feel too perfect, too smooth and evenly refective etc. Really, that would be my major bit of advice overall: things are too clean. The level of complexity necessary for photo-realism seems to be missing in some key areas.
I suspect you got the flat comment not so much because overall contrast isn't there, but because the larger/broader surfaces feel a bit flat due to the evenness of the models and textures. A really good thing you could do might be to go through and just rough things up and see how it feels. Break edges on the corners and make the materials subtly uneven so they feel more real. It doesn't have to be over the top, but it would help. I would probably do it in post now, but that's just my workflow - you could re-tool and re-render just as well. Depends on your skill set maybe, but I suspect the post route would be faster though - sorry Mike Verta
You may want to adjust the railings as Bubbaloo suggested, but it depends on what kind of material they are supposed to be. They feel a bit dark, but that might be just right for what you had in mind.
Aside from that I think some of the key areas where you could improve realism are the grass and the vegetation in general. I think the trees etc were "nicer" and fuller in the first one, but the MW version reads more real to me. The grass needs work in both IMO. Displacement would help, but you could cheat it by painting/cloning up a rough edge wherever it crosses other things (like that first step/stone) and that would help a lot. It's a trick I use in 2D work all the time. PM me and I can shoot you a good tip on how to do that if you want. Use the same principle and breakup the shadows of the structure and plants on the grass too. The grass probably needs hint of sharpening/ micro-constrast to help get the feel of individual blades in there too - it's a bit smooth for the scene lighting, at least to my eye.
I know you like those red plants but they are not helping you in the realism arena. I'm not saying you have to, but if you just took those out the whole thing would take a big step towards realism IMO. In any event, you are fighting an uphill battle with CG vegetation being so strong here. I have very rarely seen it done in a way that is convincing enough to be foreground elements. Just my .02
If you find that doesn't do the trick for you I would also suggest increasing the exposure on the background elements and letting them get just a bit hotter and maybe add a slight bit of DOF too - they can help carry you over that realism edge a bit further too perhaps.
Anyway - you're not that badly off here IMO, just some tweaking really.
b