Marauder Bombers aren't too scary in the final analysis - especially in Spearhead where they'll start the game getting a pen hit.
Spearhead has a lot of super fun 'SPearhead formations' you can take. The ones that spring to mind immediately for DE are;
Tank Hunter - you can give up to 3 Ravagers the Tank Hunter universal special rule for 60 points. That's pretty sweet,
Skystorm - Reserved transports that, when they enter, can move 36", still fire a weapon, and the units inside can disembark and assault that turn.
There's a pretty good one for Talos - it gives them Rage (boo!) but it also gives them Furious Charge and Fleet - if you run WWP it is most excellent.
Seek and Destroy - lets you shoot one weapon after turbo-boosting/moving flat out.
You'll also get to start up in your opponent's grill to a certain extent, so Blasters and the ilk are all still good. Overall I think my advice is just to have fun with it, the one game of Spearhead I played felt like Apoc-lite as it was mostly an excuse to just drop a ton of mech on the table.