I'll chime up.... considering your mentions I'll throw a few things out there.
" I am interested in a few brands, mainly Splawn and Bogner"
I have had plenty of other Splawns and Marshalls modded by Scott... Currently:
JCM800 from when he was rumored to get a tap on the shoulder saying he couldn't do that."
Splawn Quick Rod from 06' Heyboers
1959 Super Lead I recently acquired in trade for my sustainer
".... still retains the Marshall voicing."
Do I think the Splawn has a Marshall voicing? Kind of. When I play my Quick Rod versus his modded marshalls, I really truly think part of that sound does come from the stock marshall trannies. To me, the Quick Rod, Nitro etc all have a little bit of a different flavor or sound from his amps. I do however like both. To me, the Marshalls still seem "Chimey-er"
" I hate using overdrives and just to rely on the amps distortion."
You are me sir... Regardless where I played out, Arena's, Racetrack, Venue's... I'd be the guy loading in my refrigerator cases and the sound guy would start shaking his head.... two minutes later, I'd place one 57 in front of the mark on my lower 4x12, ask him to bring it up and within a minute ask him for a touch of reverb or delay from the board... I never relied on anything besides my amp, the room and the speakers.
I tell you this so you understand, you sound like our preferences are aligned... Raw tone.
"The feel of the Friedman is very chewy -- it's like you're using your pick against putty."
I don't know whether it's my attack, my ears or not running delays but my biggest issue with the Quick Rod is it always sounds chewier and more 80's in clips than my amps. I have always wanted the more chewier, saggy tone from those amps than they deliver.
FWIW: I am one of those weirdos who plays hair metal/80's rock etc with a .73 - .60 and rakes the strings while still thinking "This attack is tight!"
"I kind of miss the more instant attack and wonder if these other amp options would be better for that."
Again, to me, they seem more compressed and less chewy than my actual vintage marshalls.
At large my take is this: Based on what you're asking for and considering the prices you can pickup a Quick Rod for you might want to try one. My other opinion, Scott is one of the nicest dudes I've ever dealt with and I'm certain he would be a wealth of knowledge for these questions. It really sounds like you need a QR or a Nitro. Hope that helps.. Give Scott a call.