As a former Grado fan, I would say the W5000 works for me much better than any Grado I tried (except HP-X and PS-1 which i haven't auditioned)
The heavy coloration of the Grado just made me want something else, it's not something I can live with for a long period of time (listening and overall).
The W5k have great PRAT, superb pinpoint imaging and great response/fast attack when needed.
They are very very detailed(micro and macro) but not harsh/sharp or bright.
The layer/instrument separation is by far the best I have heard, a really good one, it comes really handy/useful in rock/metal recordings.
The midrange is a bit forward with slight coloration, probably the slightest i have heard so far.
They do have a few issues and disadvantages: small sound, small quantity of bass/mid-bass, extremely sensitive to the source, doesn't have much gainfrom an amp like other cans, for me it's a pity as I have invested a lot of money in the amplification, though it's changeable.
I consider them to be really really good as an allarounder, they perform very well with any kind of music, mostly rock I would say.