I have had both, and the DX3s is a great radio, the only problem I have with it is that it is a little 'flimsy' in construction. Mine has taken a hammering, and I have had it in pieces many times. I like all the features, 10 model-mem, expo, telemetry and all the other stuff. It also runs off 4 x AA batts which is convenient.
The 3.0 is not as feature-full, but it is definately tougher. It does not have expo or telemetry but is a very capable radio.
I would also suggest the newer model, they seem to be a good price locally and support is previously UNHEARD of....
..I cannot comment on the Spektrum servo's but I hear they are 'not all that', I have tried the TowerPro ones and for US$10, they are ok....so much of a muchness in cost I think...