Kaneda,
I have the Lucido C10 / Lightwave 4000 and I recently bought my girlfriend an Inova X5 for her birthday.
To be honest I really like both these lights, they both have much to offer and perform excellently for what they were designed for.
The Lucido C10 is brighter than the Inova X5 but then it has twice the amount of LEDs .
If I take the most powerful 4 LED light I have (the Black Diamond Moonlight) and throw that in the mix the X5 is closer in brightness to the Lucido C10 than it is to the Moonlight.
The Lucido has a wider beam as well, it completely lights up a room.
If you are planning on using the light a lot I would go for the Lucido C10, if you consider the amount of light you get for the amount of money needed to power the light the C10 is a hard one to beat.
On the downside the C10 does not make for a good EDC unless a part of your daily attire happens to be a back pack.
If my entire light collection was lost the C10 / Lightwave 4000 would be one of the first ones I would replace, but then if my entire light collection was lost I'd probably be sitting in a dark room hugging my knees whilst rocking backwards and forwards mumbling.
Sorry I'm drifting off topic a bit here, anyway back to the C10, yes I like mine.
EDIT:
Sorry I just noticed you asked if the Lucido C10 was brighter
(and better) ) than the X5.
This is only my opinion of course but no, I would not say the C10 is better than the X5, they both do very well for what they were designed to do, the X5 is a great light.
Grummond.