My current setup is an 8-gallon aluminum kettle with a weldless valve and Blichmann Brewmometer (which, even when 'shielded' from flame, does not work, not happy with that investment).  This serves as MLT and brew kettle.  I live in a tiny rowhouse with no yard so I brew in my kitchen, but have a decent range and can get a 6.5 gallon volume up to boil in about 20-30 minutes with 3 burners going.  

What I have been enjoying quite a bit is mashing to a high gravity, say for example, 1.090, collecting 8 ish gallons between lauter and 1-2 sparges, splitting into two buckets, diluting to a 'sessionable' gravity (say 1.055-60), then doing two separate 6-6.5 gallon boils with different hop additions and/or different yeast/fermentations.  In some cases, I will do a 30 minute specialty steep on one of the two batches (for example, to make a twin IPA and black IPA).  Part of the motivation for this process is to isolate certain ingredients/procedures and taste side-by-side, and part of it is to maximize my 'time-spent-brewing : beer made' ratio.  

My questions are for AG and extract brewers regarding dilution.  I have made a few extract batches recently, and seem to (may be in my head) notice a lack of body to my beers. I notice something similar with my split-batch obsession, though typically, friends/family/fellow brewers dig them.  Also, I am hitting my desired concentration of sugars after diluting.  

I have listened to both sides of the argument of hop utilization (ie different amounts extracted with concentrated boils), and don't really have an opinion, but does anyone see any glaring issues with this brewing this way?