Matterhorn is the same track layout as WDW's Space Mountain. The difference is it is not in the dark (for the most part), since it is not inside building and I don't think the Matterhorn is as fast.
Ah, good to have that in the back of my mind so that I can watch for the reports directly from DL and have the family prepared if we won't get to ride it.
As WDW vets we're used to the idea, difficult though it may be, that on any given trip you might not get to do the thing you were most looking forward to or that you love best -- I figure it's always just a good excuse to plan a return trip!
I think that the Matterhorn is more tame than WDW's BTMRR. Big Thunder at DLR is a lot less jerky than BTMRR at WDW, so if you can get on WDW's BRMRR, then the Matterhorn will be a piece of cake . The Matterhorn is one of my favorite rides at DLR, not too fast and it doesn't give me a headache or make me dizzy. I rode it for the first time in over 13 years this June, and loved it. Rode it twice, once on each side. I hope it's open for your trip in April!