I'm actually looking at the Manix 2 Lightweight. BD-1 steel which I'm skeptical of, FRCP handle, no liners, pin construction.
I'm making the decision tonight. It'll be my first Spyderco.
I can't speak to the Delica. I don't have one, nor have I handled one so take my comments with that in mind. But I do have a sprint run Endura Damascus. I also have 3 Manix 2s. IMHO, the Manix line is far more suitable to my needs than the Endura line. That isn't a knock on the Endura, instead it is a compliment to the Manix.
One of my Manix 2s is the translucent blue lightweight BD1. I have no issue with it. In fact, I love it. When I first unboxed the knife, I was disappointed. The handle seemed cheap - until I used the knife awhile and realized the benefit of the weight reduction. No issues with the steel. The BD1 steel is just fine. I've already used that Manix quite a bit and in some heavy situations. Held the edge fine and took to a quick honing like a champ. Very pleased. In fact, that is my Manix of choice right now. The Manix is a superb slicer and the handle design (from an ergonomic POV) is simply outstanding. The Manix line feels very solid and secure in my hand.
Being a sprint run, my Endura is destined to be a safe queen, so it has received minimal use. But it is not nearly as comfortable in my hand as are the Manix knives. Not bad, but the Manix is exceptional. Let me put it this way...I bought the Endura, a PM2, a Military, and a Manix XL all within a week of each other. I've since bought more Manix knives and have one more to buy when it is released later this year. I will buy another PM2, if I can find a black/black but have no intentions of buying another Endura or Military. That says tons about my opinion of the Manix. I have very few doubles of anything but I have multiples with the Manix.
All that said, it is just my opinion. Others (perhaps you) might feel differently, but all I can do is give you my thoughts on the knives. YMMV.
Best of luck making your decision.
An older pic. Note the Manix 2 XL, the PM2, and the Translucent Blue Manix 2 from bottom up.