Your Dynavector has not lost any sound quality, it should just be starting to sound great at 150 hours. Make sure your stylus remains clean and for that use the Magic Eraser to remove any caked-on bits that kill the sound.
In terms of your specific question, "Looking for a smoother top end, less noise and better bass than 10X5", the Salsa will not give you any of those qualities over the Dynavector. Quite the opposite, actually.
In terms of your specific question, "Looking for a smoother top end, less noise and better bass than 10X5", the Salsa will not give you any of those qualities over the Dynavector. Quite the opposite, actually.