I'm a huge Maiden fan and have been for more decades than I care to remember. To my mind the Crawler is too dark and the Nailbomb is definitely too modern, tight and aggressive. I hate to say it, but the pickup that best fits what you're after is without doubt the Holydiver. I do appreciate the difficulty you have because I've got a Holydiver in my Jackson so when it came to thinking of a new pup for my PRS I was sure I wanted something different. However, after much thought, lots of discussion on the forum and a conversation with Tim, I eventually decided to go with a Holydiver again. It really is a VERY versatile pickup and regardless of what it says on the website, I've found it to be far more versatile than the Nailbomb, which never seemed able to lose its 90s Metal feel.
Having said that, if you REALLY want something different to the Holydiver, I'd like to suggest the Abraxas. In terms of power and EQ, it's not massively different to the Super Distortion that is a key part of Maiden's sound and although I'll grant you that an Alnico IV magnet is very different to ceramic, it is articulate enough to carry it off and give you genuine versatility that a Super Distortion wouldn't. Look at it this way; if Tim can do Ozzy Osbourne with a Mule, you can certainly do Maiden with an Abraxas, which is often referred to as a hotter Mule.