speed control and blip in power?

The "Odyssey Lerch" that you see is an issue with the early Odyssey versions, the Legacy stuff with Odyssey II doesn't have that issue.  Currently, for the retrofit market, the ERR products are the only game in town for TMCC layouts.  There are other speed controls for TMCC, though they're not commercially available anymore.  The TAS EOB system is one, and the K-Line cruise control is another.  Of course, if you have DCS, the PS2/3 electronics also has speed control.

 

I don't notice any significant issues with the ERR CC or CCM.  However, if the locomotive totally loses power over a switch, it's perfectly understandable that it would momentarily slow down until power is restored.  On steamers, which is where I have the most issue with switch transitions, I've taken to adding pickups to the tenders if they don't have them and connecting power through the tether between the locomotive and tender.  Other than small units like the RMT BEEP or similar, I don't have issues with diesels on switches as a rule.  Note that many of the Legacy locomotives have extra center rail pickups to minimize issue over switches as well.

 

I removed the switches on my longest loop and everything runs great on it.
  I only have one switch on the main line on my inner loop. It is o27 and the locos I run on it run fine.  I am leaning twards adding cruise to another loco.  Don

Many times you can do some work on the switch to improve things, depending on the switch type. 

My guess would be two possibilities, the engine going through the switch is being slow downed by guard rails, being  narrow and pinching the wheels or the wheels themselves being a little out of gauge. Here s my theory, with cruise the engine is set at a specific speed, now if you put a little drag (or load) on the engine the cruise is going to compensate and raise the speed of the engine to maintain speed, now you are clear of the switch and the speed returns to set speed. 

 You can try this on your track by putting your hand in front of the engine and with a little pressure you will notice that it will try and speed up and when you remove your hand it will return to set speed.

 

Bill

Bill, as I know you're aware, early Odyssey had the "lerch" issue whenever power was interrupted.