Any good reasons to use transistor phono stage and line level preamp instead of tube ?

@sbank

Nevertheless my statement is true.

FWIW we've done a lot in the last 18 years or so since you had your MP-3 (yes- it really been that long!) to eliminate RFI susceptibility in our preamps. 
Tubes are actually less susceptible than solid state; this is because solid state devices employ diodes in the junctions of the semiconductors. So a solid state designer really has to be aware of RFI issues. With tubes you can often get away without because there is no diode inside a tube to rectify RFI and make it audible. Until of course, the RFI is so powerful than other elements in the circuit do it anyway. Because we had to meet EU directives (CE mark) and because people like you occasionally live by radio towers we had to do something about it and we did so years ago- in fact your experience underlined to us that there was a problem and so we had to address it.

There is no such thing as a "tube" sound or a "transistor" sound! Contrary to what the untutored believe!

This statement is false although it should not be...
Transistors make more higher ordered harmonics than tubes do, that that is why there is a tube/transistor debate. If there was not 'sound' there would be no debate.

Tube phono stages are going to more susceptible to RFI if you are near a radio tower.

@sbank
This statement is false. Tubes are no more susceptible to RFI, if anything they are less so (because they don't have diodes integral to their construction that can rectify RF). Its really a design thing, whether or not the designer paid attention to RFI issues. So do, some don't.