I'm a little unclear from your post. Do you have two half-days or 2 1/2 days? If it's the former, I think you have time for both parks. If it's just two half days, you might want to focus on Disneyland with possible starting in DCA on the second half day and then crossing the esplanade to close out DL when you're done.
I'm not a huge DCA fan, but it's growing on me (and I've only been there once). Check up on the attractions and see what interests you. I wouldn't skip Soarin' just because it's at Epcot. It started here, and the theming is differeing though the ride experience is identical. Grizzly River Rapids is a great water ride, much longer and improved over Kali River Rapids, but you will probably get quite wet.
We had no problems with the California Screamin' and found it quite fun. We also enjoyed the Sunwheel, but left the other Paradise Pier attractions alone because they are pretty common in carnivals and on boardwalks - but that's the theme!
Tower of Terror is different than MGM, and I think a little inferior, but it's a good experience if you have time. Monster's Inc is unique (for now) to DCA and gets good reviews. The real time killer in the Hollywood Backlot will be Aladdin. If you're a worship leader, you will appreciate the production values of this show. It's probably Disney's greatest stage show anywhere except Broadway, but it's a time killer - at least an hour including wait times, maybe longer.
In Disneyland, all the attrations are great and pretty much as described. However, Space Mountain is a major upgrade over WDW and Fantasmic! is a very different experience than in WDW. "Remember . . Dreams Come True" should not be missed if you like fireworks - Disney's longest yet, and the variety of shells and launch points is jaw-dropping. You'll be faked out because it starts like Wishes, but then moves to a sentimental 'lump-in-the-throat' moment when you hear Walt's voice before the beginning the main part of the show.
You can see Fantasmic! and Remember in the same night but it's tough. If you do this, see Remember from Main Street, near the hub, and then, as soon as it ends, do whatever you can to get over to New Orleans Square for the second showing of F!. You're best bet will be to get through or around the east (Tomorrowland) side of the castle (if possible) or just go through Tomorrowland. The hoards of people exiting will make it difficult, but you can do if you are just adult or are by yourself. You need to go the roundabout way because not only are the Remember crowds heading out, the crowds from the first showing of F! have been trapped in New Orleans Square and they are also heading out.
Then, once you get to NO Square, if you can get a good view of the cabin in Tom Sawyer's Island, you're set.
Personally, if I had two half-days, I'd probably forget DCA exists, or just go in to wander through and see an attraction or two before fnishing up in DL. With 2 and 2 1/2 days, you could easily see DCA in half-day by being judicious with your attractions. If you did manage to see F! and Remember in one night, you could try for Disney's Electrical Parade in DCA at 8:45 and then hop back to DL. It's a cute classic to enjoy if you have time, but not as amazing as the DL nighttime shows.
Have fun!
Dirk