Ironically, the only significant tube delay we experienced was just before our very last stop, ever. So we stood for 15 minutes with our backpacks on, waiting to exit the tube and run for our morning train. Luckily, all was sorted out well.
The train ride takes ~1.5 hours from London to York (we booked an express route). Nice countryside views, but nothing breathtaking. A few windmill farms, but not as many as you'd find nuke plants, oil wells, and fracker pumps comparatively in the U.S.