@honeyooi , The link is well worth a read, it will certainly offer you a reassurance that your use of a SUT is totally acceptable as choice.
Audiogon Discussion Forum
I like yourself, have wed myself to Valves.
Like yourself, I have been able to experience the impact of Late 50's/ Early 60's Input and Output tubes on owned devices and have been left very very impressed.
I have in use a SUT > Valve Input / Output Phonostage and a option regularly put in to use of a MM/MC Valve Hybrid Phonostage.
Additionally to this I have also got access when wanted to add a Head Amp in place of a SUT.
There is not one set up being experienced that can be referred to as inferior, but the set up's can lend themselves to allowing the recording engineers work to be replayed in a way, that is seemingly aligned to what the engineers intentions was to produce. Using the available permutations, I have always perceived a Wide, Deep, Soundstage with ample Headroom. I have never felt notes/vocals were not being resented with an honesty and do not detect any smearing or coloration. I only detect that each has the capability to add its own traits to the Sonic.
To give an idea of what I am referring to, Pink Floyd's the Wall Album has been the same copy owned since it was released. This Album has travelled far with me and been experienced on many many systems when demo's are being attended.
At no time has the Helicopter on the Album been able to descend and land in the listening space, it has been overwhelmingly present, as it was in a low height hover, but not perceived as a descending aircraft approaching to land.
The only Phon' I have been in the company off that achieves this, is the Head Amp > Valve Hybrid.
Did the Sound Engineer, produce a Helicopter impression that was of one hovering at a low height, ot one that was descending to land? I feel confident my experiences has determined that answer, for myself anyway.
In direct response to your inquiry, I have evolved in my ownership of TT's and moved on from Belt Drives to Idler Drives and now use Direct Drives. I do still own all three drive types and can when the system is set up, put any one into use in a short duration of time.
When moving over to my most recent DD>TA, I changed from having a SME IV and Audiomods Series Five Micrometer as the main in use TA's.
After being demo'd a alternative design for a TA against the SME IV, the evidence was present that the SME IV was surpassed and not too far on, was superseded by the earlier demo'd TA.
I also discovered at a very similar time, I desired to change the TT Drive from Idler with redesigned Platter Bearing and Speed Control to a DD TT.
The DD TT has also undergone modification on the Platter Bearing, Speed Control and method used for mounting it.
I feel confident that by experiencing alternative TA's on your set up, a discovery can be made that will prove extremely satisfactory.
My advisory would be to have a Standalone Tonearm Base to use the alternative TA's on, when being used as a comparison to the owned TA's. A little bit of pre planning and marking out the needed Geometry and height requirements should enable the Standalone Pod to be quickly positioned on any TT, it is wished to be experienced on.
If an alternative TA, makes a very good impression, even when being open minded and considering one such as the Viv Labs Rigid Float, it is then advisable to set it up on the TT, as per the method it will be used in the long-term.
I don't know if your TA's are incorporating a detachable Headshell, which might add risks, if comparisons are desired to be carried out with a preferred Cart'.
The following is real, and as strange as it might appear to some, especially the 'anti' SUT, Standalone Pod, Underhung Geometry Brigade.
A friend has a Glanz 12" Arm > Miyajima Cart' mounted on a Home Designed, machine shop produced, Standalone Arm Pod, which is in use with a SUT and SP10 R. I genuinely can't detect how an alternative method, and working within a certain budget, to amplify the current/signal and change of TA mounting method, is able to improve on the extremely good impression already being made. I'm also not close minded and do suspect that if thoughtful changes/adaptions are put in place, something new will be experienced, but bettered will have to be proved.