@Jim L I don't have SR-L700, but you're right on the 10 staxens collection, which is barely acceptable for someone posting down there...hey, I'm no 007mk1 lover and don't have any clue in electronics, so be gentle.
Not so much to add to @Sorrodje's impressions. I could have written exactly the same statement on amp's ranking on HE60, as well as how far modded 727 stands from the two other contenders of the day.
My opinion is a little bit different for 009, as I would insert two or three more ">" between BHSE and SRX+. No mystery I'm 009 lover, HD800 are probably my favorite non stat, but my tastes aren't exactly the same as Sorrodje's, so I value a bit more kick in the low-end, control, amount of details and soundstage provided by the BHSE's. Q/P ratio remains always on the cheaper one, don't mistake me, worn-out diminishing returns platitude in audio.
SRX+ is not as "right" as BHSE, but there's something very funny and energetic in its presentation. Think about the low-medium kick and foot tapping thing you can get from SRD-7 + good ol' 2-channels amp, but with detail retrieval and soundstage you have on a very good dedicated amp, way way above modded 727 level even if some steps under BHSE's. When listening to 009 on SRX+, I was thinking about my Lambda Signature on steroids, kinda vintage sound, with 009 details and technicality (and Sorrodje loves Lambda Signature )
007 are another story, as my main concern with them is their lack of dynamic compared to what I like. BHSE raises them at pretty good level at last, but on the same amp, they can't compete with my other Staxen's regarding dynamics IMO (main exception : Lambda Nova Signature). So the transformer-like sound exhibited by SRX+ (again, with details and soundstage from top notch dedicated amp) may be my choice to get the best experience with those unloved ones.
Ali