I lived with a SF Line 1 paired up with an SMc modded McCormack DNA-1 for several years and felt they worked well together. Enough that I lusted after the Line 2 as a future upgrade.
While not familiar with the Arros, the SF and DNA are not a combination I'd mate with any speaker prone to HF glare. The slightly dry nature of the Line 1 accentuated an edgy character in the upper frequencies of my speaker's metal dome tweeters. Rolling in the right tubes mostly tamed it.
My recollection is the Line 2 lacks the 1's dryness, though neither is a really tubey sounding preamp.
Hope that's helpful.