Sound Equipped vs Installing it yourself?

[Jake]

I have always been wondering this since Bachmann started the HO scale DCC & Sound Onboard models. My thing is, what is the real difference between the "special" Tsunami in the pre-equipped engines and a retail one? I also know that the on board engines are not hard-synced with a cam. Are they reasonably soft synced? Because while I do not care where the sound comes from on the engine (unlike a few of us ) an off-synced engine is one thing I will NOT have. And if it is oddly synced, is there a way to correct it, or, preferably a way to install a cam? Does buying it with the decoder equipped save a bit of time? (Well obviously it does, but if the retail Tsunami take 5-10 mins to install, and isn't stupifyingly hard it doesn't matter to me, I will go with what is less expensive!) And that basically covers all I want to know! Thank you in advance!

[SteamGene]

The Tsunami that comes with the sound Spectrums does not have all the bells and whistles of the regular one.  However, it is possible to synchronize the chuff with the wheels on all the sound decoders I have.  Some just take more time than others.
Gene

[Virginian]

Got to agree with Gene.  None of my sound engines had a working hard cam synchronization set up, but all of them have the wheels and cam in synch up past where one can accurately see the wheels whirling around.  Only one did not come that way from the factory, and it was easy to rectify.

[Jake]

I'm sorry virginian, could you repat that? lol.