Something about the W5000 sound is just so damn exciting. No shit, I keep forgetting to breathe when I listen to them. They sound so unheadphone-like, but by that I don't mean speaker-like. Acoustic guitar plucks in particular sound marvelous. Bass actually has a nice heft and flow to it, I'm thinking this is because the cups sit flush against my large square head (one of the big complaints I read about the W5000 is that the top of the cups don't sit flush, thereby leaving a nice open area for all that bass to escape). The soundstage is remarkably large for a closed can.
I attribute the can's "excitement" to a combination of the hot/wonky midrange and overall PRaT excellence.
It was when I bought the Aqvox that I really started to enjoy this can. All of the above impressions are based on a Aqvox > Dynahi > W5000 setup. The Melos was also very nice with the W5000, but the Dynahi just eeks out that extra detail and space. However, I've recently been browsing the internet for additonal amplification options, which the sale of a W11JPN could help procure.