For me, TSA design looks old fashioned like FCT. A little slow F ratio set it better than FCT, maybe.
Comparing MK or reflectors, both still have false colors in my eye though almost negligible.
Despite, 4 inch FCT-100 looked clearly better than 6 inch Intes Makstov Newton on the Mars side by side.
It was true with my friends there, and also with Intes owner. Things seems not so easy.
Comparing DSO like NGC7000 or Vail, Every one say refractor have better contrast than more larger reflectors.
Last year, I select 10" Intes Makstov instead of FCT-150 at our star party in dark site with SQM21.87.
Every one said NGC7000 looked better on the FCT150 than 10" MAK. and I also felt it. The contrast was the matter.
TSA120 F7.5 is the successor of the FCT125 F5.6. As Tak say TSA would be better. FCT-125 was ultra rare scope, not so many reviews out there, though I hear FCT125 F5.6 has better resolution than FC-125 F8.
I did not had a chance to compare FCT to EDF-155 or TMB-150, though these are triplets the performance is not so different I think.
Though, my recent desire is to add light weight 5 inch ED doublet for grab and go. I often use FCT-76 with a little needs for the apertures. ASTRO-TECH AT125EDL may be the spot on I think. TSA-120 is expensive for me.