The reality of various manufacturers subscriber equipment operating on any P25 system, at least seamlessly, is misleading. For instance the modulation schemes (Motorola's CQPSK vs. Harris' WCQPSK) do not perform ideally on the others' simulcast systems. Also, I would encourage anyone kicking the tires on introducing subscribers by manufacturers other than those of the infrastructure manufacturer, thoroughly evaluate their performance on that system. For instance try out a Harris subscriber on a Motorola Astro 25 system in a fail soft condition. One may be surprised of the results which is contrary to "any radio on any P25 system". Not without some degradation of functionality at least.