Is there any reason not to have tube phono stage ?

After many years of having used and experienced Phonostages. I was to settle for more than one.

I maintain my first Custom Design / Build SS Phon' of approx' 35 Years Old.

Throughout 35 Years I have owned other SS and Valve Phon's.

More recently I have a Valve Input / Out Custom Produced Phonostage, with very carefully selected Vintage Valves, A Valve Hybrid Phonostage with cery carefully selected Vintage Valves, which are both keepers and always to be maintained in use.

Most recently and now ready to be picked up, I have a Custom Built SS Phonostage produced for myself.

To a Male Audiophile, Phonostages are the same as Shoes to a Lady. One is never going to suffice. Being able to mix it up for different musical encounters of much enjoyed Albums is the Goal I have set for myself.  

It depends on the particular unit, but my most recent build is a tube Hagerman Cornet 3, and I prefer it to my modified Hagerman Bugle 3 SS phono stage, which I thought was excellent.   The sound stage is deeper.  Voice inflections are more detailed. Strings in general have more texture in the overtones, and it’s more vivid and realistic.  It has an open effortless feel to it.  Pretty much the same characteristics I enjoy from my other tube gear, but there are several variables involved.  

There’s typically less cost and downside with a tube phono stage or preamp than a tube amplifier, but there are pros and cons with both formats,  It’s always a personal choice...I got hooked on tubes in the early 90s (at least for the critical music range), and  have never looked back. 

My two preferred phono stages are MM Tubes, and I use a SUT for LOMC so I can keep using the MM Tube Phono. 

Listening with my friend yesterday, he has a Project Tube Box S2, it can do either MM or MC, but the damn thing has dip switches for capacitance and impedance on the bottom of it, and no PASS for MM.

We were comparing Grace F9 MM to Goldring Eroica LX LOMC, total PITA.

https://www.project-audio.com/en/product/tube-box-s2/

Highly dependent upon the cartridge and on whether or not you use a SUT with low output cartridges. One can’t answer those questions for you. For high output cartridges I would use tubes, and I’m on record to say that paying big bucks for NOS tubes is overrated although you do want to select tubes that are operating within spec as described in the RCA tube manual. As to matching sections of dual triodes, that too is pointless if the circuit is single ended where typically only one of the two sections is in use. But can be important for balanced operation.