Looking back at your 007 vs. 009 question, you also have to compare 007mk2 to 007mk1. The latter are more praised all around and have more technicalities to my ears, but mk2 have less annoying peak in the highs, and the low-mids bump due to the leaky design adds some enjoyment to the 007 slipper's behaviour (comfy but flabby)
Ali
To state a somewhat conflicting view, I have found the mk1 to be more open sounding (more mids), more extended in the deep bass and with more sub-bass impact but with less midbass impact than the mk2/3, smoother mids, and smoother highs as well. I guess what you hear may also depend on recordings and the music genre. I usually judge sonic qualities with instrumental music. With jazz, I often preferred the mk2. With both, the 009 usually comes out more neutral and with better pitch than both 007. Still, the 007 mk1 holds up quite well, especially when considering the price, the much lighter weight, and much better head-fitting possibilities (though it's not really an issue with the 009, I like it as it is, no need for clamping force change or anything, but I'd prefer the 007 light weight and adjustments). Also, I don't find the 009 to be too bright, nor hard in the sound, especially with the BHSE.
For an newbie, I would give 90% chance that someone would like the 009, and much less chance that one would like the 007 so much that won't upgrade to the 009 (and then the whole chain) - but it does happen, either on sonic or economic grounds (diminishing returns). So there is no way out, one needs to listen to both and decide which poison to choose.