The Lucid has been considered a budget LTE phone since launch, while the RAZR has been considered a high-end LTE phone (and one that's now on sale). And that definitely shows through in the specs. The RAZR has a higher resolution screen (which is also 0.3" larger), more internal memory, much slimmer body with a premium feel (that's also water resistant), more color options (the white and purple might be something a wife would appreciate), a better camera, and better reception. The battery in the RAZR (1780mAh) is larger than the battery in the Lucid (1700mAh), but an 80 mAh difference is marginal. Smart Actions on the RAZR can make a world of difference towards improving battery life though. However, the battery in the RAZR is not removable, and that's a major concern for some. But unless you're planning to get an extended battery for the Lucid or unless your wife plans to carry around a spare battery, that won't matter in every day use. Motorola also has a much better track record on phones than LG does. Chances are, since is was a flagship phone for Verizon, the RAZR will see a longer period of official updates and support than the Lucid will. Most budget and mid-range phones are quickly forgotten about.
Given all of that, along with the fact that you already have a MAXX (which operates identically to the RAZR save for the battery), I'd definitely say it's worth the extra $20 for the RAZR. It's just a much better phone in pretty much every respect than the Lucid.