As I'm in the middle of a move I haven't spent as much time with the 4070/007t as I would like, but I'll second Waynes comments. I've found my closed cans. Coming from Lambda Sigs and Lambda Nova Sigs the extra detail/texture is the first shocker. A little slam on the bottom in comparison and a much enclosed soundstage hits after. No doubt these are closed in the soundstage department. Got lost in some Everything But The Girl about ten minutes after putting them on. Still some of the Lambda etch, which I prefer to the laid back SR-007 Mk2 with vast majority most electro amps. Then add power. I was a little worried as I didn't think the SRM-007t exposed the true differences between the Lambda Sigs and previously owned Lambda Pros, but the 4070 seems to pair well here. Source differences such as Para d/ac 1600 v. Pico were shown clearly. Though I'd like to hear other amps, with the 007ts availability and going price (not to mention a few features like balance controls), I'm happy sticking at this point. As I worried my money was mostly going for the cans closed aspect only, it's great to truly get a jump in SQ over the Lambdas (several times over the differences of the various Lambdas I own or owned). They're even tempting me to get rid of the K1000 (practicality and that low end), but going to need further tests for that.
I also tried the 4070/007t under flu-conditions. It sounded screechy, overly Grado-like in awkwardness and induced intense headaches. Not recommended.