I only tried it briefly and it seemed like an evolution of the E10 to me. Maybe my brain was playing tricks on me just because it's a soundmagic. The only other thing I had with me was the GR07, and it wasn't as neutral as that.
Really depends on what you're looking for. I tend to prefer neutral sound + silicone shells so for me it would be the Custom Art Pro 330v2 (brief writeup here: http://theheadphonelist.com/brief-impressions-custom-art-harmony-8-pro-pro-330-v2/) or an extra $100 to go 1964EARS V6-Stage (and I'd give up the silicone shells for that). But, if I was looking for a more "fun" sound with some extra bass I'd pick the 1964EARS V3. Those are sony hybrids.
Couldn't have said it better than kova4a - that has been my experience with the CIEMs you've listed (SE5 aside - haven't tried those) and others. Of course that's not to say you won't like one of them better than the ER4 overall. Just don't expect an ER4 sound signature with better clarity.
Don't have that information - my point was that it's very likely that audiologists in Westone's dealer network are more experienced when it comes to custom IEM impressions than random ones you'd find in the yellow pages.
I don't know anything about this company but impressions are definitely something you can do yourself if you are careful- see here: http://theheadphonelist.com/ear-self-impressions-for-custom-in-ear-monitors-what-you-need-to-know/ Quite a few options for enhanced-bass earphones with detachable cables among universal-fit IEMs: EarSonics Velvet, InEar StageDiver SD-3, Ultrasone IQ, Sony XBA-Z5, Sony XBA-H3, Fidue A83, Sennheiser IE80 etc. Plus some I haven't tried, like...
thx1000 posted the link. For accuracy and neutrlaity - S2. For a bassier, more v-shaped sound signature - Momentum in-ear. Yes, I just got Tyll's pair. Not sure if I will review them here or on InnerFidelity yet, but I'll get one put up.
The earphones fitting your needs/sound preferences is much more important than some number assigned to the earphones by a random headphone geek on the interwebs If the GR07's sound seems like it will resolve the issues you have with the DN-1000, it may be an upgrade for you (but perhaps not for someone else). The H3 and IE8 have more boomy bass than the DN-1000, so probably not an upgrade in this case. The SportBud has good bass quality but lower quantity (closer to GR07...