I'd be surprised if you found someone who's made that comparison, but you never know. A lot of folks here haven't even had the chance to see/hear any LSR models, especially the LSR 6332.
The LSR 6332 is arguably the best three-way bookshelf monitor ever made by JBL. I've heard them a number of times, including in JBL/Harman's Reference Listening Room in Northridge, CA. A full set up of these along with some LSR subs is quite a dream for those who've heard it.
Neither the JTR T8, JBL LSR 6332, nor the Adam Audio GTC88 is going to get you ULF, so with proper placement your dual (at least) subwoofer plan is a good one.
I'm fascinated by speakers with dual or triple small LF drivers. The Revel Salon2 is an example of the concept taken nearly to perfection, and it includes the ability to dig pretty deep in the bass. The LF specs on the JTR and Adam are less impressive, but with a sub, anything under 40Hz should be a nonissue anyway.
From a personal preference point of view, I've not held on to any 6.5", 8", or 10" dual or triple woofer speakers that I've owned. They all go bye-bye eventually. I tend to gravitate toward 12", 14", and 15" woofers in full-range speakers. The single exception is in my HT, where the Synthesis® SAM2LF units are dual 8" Al cones. Of course, they're anchored with four 18" subs in the room, so there's plenty of bottom to be found, and the SAM2LFs are doing mid bass duty only, coupled with the SAM1HF units handling mids and highs.