DLM is one of my regular jaunts! From BOH THomson usually fly the-800 as they have one or two based there I think.
Approaches - 'usually' during the summer approach over the sea but it really depends of course on the wind. As I go out winter and summer, thinking back I would say it is about a 50/50 split from over the sea or the mountains.
If over the mountains, spectacular views but can become it a bit bouncy. Always an extra tug on the seatbelt for me to tighten things up a tad before touchdown.
Was up the back of a TCX 753 a few years ago on a mountain approach. Interesting to see how looking forward through the cabin how much flexing occurs!