I've used SiTrain in the past. Course I had to take was in Atlanta, but have been asked to attend classes in St. Louis as well....Not sure of other training centers.
https://www.sitrain-lms.com/Courses.aspx
They have a training center in Troy, MI as well, which might be good info if FactoryTalktotheHand is in MI like his profile says. However, most of the classes are at the main facility in GA, so to get the right class at the right time for you in MI can be tricky. If you have enough guys to train, they might be able to add a class for you.
I've seen Simatic Manager (Step 7 v5.5, sometimes called "classic") used across the auto industry, and a lot of jobs for the big 3 still use it when they go Siemens. This supports the S7-300/400 and has been around for ages. It isn't quite "legacy" yet, but it definitely isn't the cutting edge.
TIA Portal (Step 7 V13) is starting to be used at some of the Tier 1 auto suppliers, and in other industries like aerospace. Portal came out about 5 years ago, and supports only hardware from maybe the past 10 years (S7300/400 and the newer 1200/1500).
From what I've seen, Portal is still going through growing pains to some extent. It gets rid of a lot of the things that made Simatic Manager hard to use, but some features people are used to are missing. It also pretty much requires a large monitor and a beast of a computer (though to be fair, what software doesn't these days....). New users tend to like it, but I don't think many existing end users are in a hurry to switch from Simatic Manager.