This is an ink that most everyone has, I bet, but I don't know if most really use it. I know I hadn't used it until just recently. We ended up with one more Lamy than we had converter, so I popped in the cart that came with the pen. It's actually a pretty nice blue. It's not blowing anyone's doors off, but it does the job.
The color is nice enough, and there's a bit of a sheen to it if you lay it down heavily. My Lamy pens tend to be just a bit on the dry side, so I don't see this in the writing. It behaves itself on common papers, and actually looks a bit better than it does on Rhodia. I think the somewhat thin nature of this ink makes it look anemic on Rhodia whereas it soaks in more to the regular papers and looks more saturated.
If you're a cartridge user, this one is just fine. I like the turquoise better, but the Blue is pretty good.
If these, the Lamy ink is the weakest. The others are certainly darker, with the Montblanc being barely a blue at all (once it dries).
Copy Paper Test
If nothing else, the Lamy ink is very well behaved on copy paper.
Water Drop Test and Review Video
So, in the final analysis, the Blue from Lamy is a perfectly fine ink, if not a super-impressive one. It gets the job done much better than most other included cartridges, I think. I'm generallynot all that excited by the cartridges that come with pens, but these are totally usable.
Find it in bottles, cartridges, and samples at lots of stores including Anderson Pens. (The Andersons didn't give me this ink, but they're friends of the site, so tell 'em I said "Hi!" if you order from them!)