If you think the Dynavector 10X5 has lost some of it's sound quality after only 150 hours, you should check to make sure you have it mounted correctly. You should get at least 10 times that much play before a cartridge starts to wind down. Here is a couple links that may help.
Understanding The Issues Behind Cartridge Alignment
Cartridge Alignment Protractors
Understanding The Issues Behind Cartridge Alignment
Cartridge Alignment Protractors