I prefer Nightstand Central, especially since I'm the developer
Alarm Clock Pro is nice for what it is, though.
Nightstand Central has more features that you may or not find useful, like a sleep timer, better looks (IMHO), and photo backgrounds. Try the free versions of both and see which one you like more, I guess.
I just wish it was a Universal App b/c paying twice sucks even though it's a small Fee.
I know what you mean. Believe me, I wish that I could let you have both versions for one price, but there are just too many disadvantages to the Universal app approach from my perspective as a developer (rankings are counted depending on which device the app is bought from, new releases don't gain as much publicity, file size must be larger to accommodate resources for both versions, etc.). Alarm Clock Pro is not a universal app either, probably for many of the same reasons.