I have only seen that problem once myself and it was when I consist my bachmann gp38 with another loco. I assume it was speed matching problems but why it jerks down the hill is unknown.

Oh sorry that was kato.

I believe that was the n scale version but that just means it will be even easier in ho

I personally prefer to kill the shiny look with dullcote and powders. Wheels can be easily and cheaply detailed and painted to a less shiny shiny silver to a better grungy gray. And it all depends on how much weathering you want to do to it.

It shouldn't be too hard to just find a trouble spot and carefully watch the loco, if it is the coupler than it should be quite obvious. And ho ron I'm guessing by "coupler airhose" you mean the trip pin

The zepher is a very good choice and not to expensive.

Haha you remind me of a small cartoon I saw in a train magazine, where a guy has a huge list and buys everything in one load and then buys a shovel and his modelrailroad friend asks what it's for and he says" if I'm going to have a model railroad like yours, I need a basement first"
Anyways the message is take it slow, the enthusiasm Is great but don't  and buy everything at once. Over time you find rare sales/deals and eventually growing your locomotive and car roster.
Good luck
Sorry about the comic description:)

I had to add weight to the tender of my GS4

Wow that's much better than the previous plastic wheels and horn hook couplers. I'm suprised, though I haven't seen any of these kits. Now all they have to do is upgrade the kits with all the great details and etched metal parts like the RTR models

Could be the decoder, if you have the ability to pull out the decoder and test it that might be the best thing. But be careful if you do do that to not reck anything just in case that's not the problem and you need to return it. I have one bachmann gp38 with dcc and it has had mo problems and generally runs very well

What company are they?

I'm a full CPR modeller, specifically modern stuff and I've noticed that athearns really the only company selling them. Being that the CPR has so many I think there should be some more sources. So a bachmann AC4400 would be awsome. I also love the CPR selkirks and hudsons, need some of those too!

Steel works fine it just gets dirty faster

I believe the switchs get their signal the Same way as locomotives, through the track. But unlike the locomotives they probably don't have the ability to run on DC. Their kind of useless on DC so I don't see why you would be using them on DC?

Yeah kadee has kits for that conversion and will work much better