Which is best would you say? And which translates over to TSW2 best? I'm tempted by Peninsula Corridor because a nice long 47 miles. No idea how long the Tees Valley line is.
I only own TVL so I can't comment on Peninsula Corridor. But I can say that TVL is a great route which is well built and very atmospheric. If you like goods trains, I think you'll like this route with the class 37 coming with the route, and the 31 and 20 available as DLC, also don't forget the class 08 which is used on shunting duties in the yard. Even if you're not too fond of freight trains, which I'm overly not to be honest, there's the 101 to drive on passenger services. The full run between Darlington and Saltburn-by-the-Sea is of descent length at around an hour but there's also shorter services between Darlington and Middlesbrough which are about 25 mins long. Once you get the hang of driving the 101, it is a satisfying drive which keeps you on your toes. Tees Valley Line is just under 28 miles between Darlington and Saltburn but if you consider the massive amount of sidings and yards along the route, it's actually much longer.
I would second the Tees Valley Line for all the reasons mentioned by Northerner above. It is a great route with some nice landmarks along it. It also feels busy, and running the freight trains you come up against yellow signals. I purchased this DLC without much expectation, but ended up loving it.
It would mostly depend on your preference of country as both routes are similar in terms of what you can do, I own both and I like them both for different reasons. TVL is good because I like the old fashioned grimy aesthetic that the route has. It is more freight orientated but as others have said, it does have a nice passenger run in the 101. Pen Cor is also a good route mainly down to the nice scenery, the long straights and the big US Locos (the doors have a lovely opening chime too!) It also has a bit of freight movement too although not as much as TVL. The Baby Bullet add on is good too with its nice spacious and clean (compared to the TVL locos) cab. In terms of performance, they both seem to run better on TSW2 than originally but neither one seems to be better than the other for me on my standard PS4. (I don't have either route on my XBOX, sorry!) If you’re patient, you might want to wait for a sale where you might be able to get them both for the price of one (or thereabouts). Unfortunately, sales for TSW seem to be far less sporadic than on the PlayStation store.
I own both on PC. Personally, I would say that while both routes offer freight and passenger services, TVL focuses on freight and Peninsula Corridor on passenger. I feel like PEC is quite challenging in terms of passenger services, because the trains get very fast between stations and you need to know your break timing well to do perfect stops and stay in time. TVL has the class 101 passenger train which has manual shifting. This is unique and for me alot of fun. Both routes have great scenery and you feel absolutely immersed in both of them. TVL has a shunting Loco which adds another layer of gameplay and is also great, PEC has shunting as well but only with another dlc MP15(which is also a great Loco) Overall I enjoy both, and usually play PEC more often. But objectively I would recommend TVL between these two.
Good points made above- i'd just add that I think they're two of the best routes available on TSW/TSW2, especially with the additional DLC. They are both fun to drive, have good amounts of AI traffic, and feature interesting scenery.
Differents but also similars cause are both very "solid/complete" DLCs. With all add-ons, personally I prefer TVL as first choice.
I prefer PEC, I just really enjoy the trainsets. The baby bullet is amazing to drive but the included F40 is no slouch either. These trains have honestly the best sound design in the game imo and are a lot of fun. There is a lot of different passenger services; local all stops, fast with limited stops and baby bullet express to keep you busy for a while. You can drive freight services as well with the GP38. Obviously you run a lot of times into red signals as this is a very busy commuter railway. There are two DLC locomotives: MP36 Baby Bullet and the MP15 switcher, both are outstanding as well. The route is beautifully crafted and absolutely nails the Californian vibe (I actually rode the Caltrain a couple of times irl so I know what I’m talking about). To me, honestly it’s on the same level of ECW if not better because of the amount of different services you can experience The signaling system is also very demanding as there is a lot of different speed limit combinations and approach signals so that’s a lot of fun to master as well