Just been and finished the 12th activity, 4 more to go. The first activity crashed for me too twice. The work-around for that was to turn the World Objects Density down to zero and see if it loaded. Which it did. I then went a few miles out, saved and put the same setting back to the previous setting (which for me has to be 6, this poor laptop doesn't like anything higher) and carried on as normal. Thanks must go to expressboy1983 for that tip.
Thankfully, I saved fairly regularly. This proved hugely useful when MSTS then decided to change a green signal at the west end of the platform at Chadwell Heath to a red one as I got to it. It took me quite some time to get used to how the brakes worked on the 86, as compared to the 90 it was an entirely different beast. Loved the sounds off it though. Managed to make it to Liverpool Street, with some unintentional speeding through Chelmsford (due to that braking problem mentioned above), 4 seconds early, even though it meant leaving the DBSO off the platform!
I've enjoyed the activities I've done so far, although I was ready to just save, quit and come back to the 170 on the Harwich to Norwich stopper after departing Ipswich! That was another train I had problems with braking with, the sheer amount of braking required for stopping in places seemed to be maddening huge.
As for the DVT, once I worked out (surprisingly quickly compared to the 86) how the brakes worked I had next to no problems there. That 153 cab on the late night Norwich to Ipswich stopper is far too dark, although for most of that activity I was bored enough (sorry, but it's hardly an exciting act!) to use views 2/3/4!
I've now started my own two-part activity using a Deltic and an 87, although there's a lot of work to go until it's ready for uploading. expressboy1983, tubemad, if you're reading this I'm going to need some help and expect some of my hair to be pulled out!

English Electric loco nutter, you can keep your Sulzers! If it's electric, it had better be an 87!