Stax, better newer or older?

Hi Stax fans,

I am in the market for a used Stax setup. I have read a couple of comments about the older models (Lambda Pro, Sig's etc) being better or at least as good as the newer (303, 404) offerings. What are your thoughts on this? What about the amps? For example, a 3003 setup can be had for about the same as an older Lambda Sig/amp combo. Which would offer better performance? Put yet another way: how do the new bottom/mid of the line cans compare to the older top of the line?

Thanks in advance
To me, the older Lambdas had a different balance than the 404s which I own now. The 404 has better bass and is less bright than the original Lambda, as I recall. That said, I think some of the older Stax phones sound great. I have a set of the "New SR-3" phones (really old model!) that I think sound great, though not as detailed or as extended in the bass as the 404s. I run them both off the Stax 006t tube amp. Whichever Stax phones you end up with, I don't think you can go too far wrong.