Originally posted by calsan All the limiteds whether DA or FA are metal and the best quality for the given aperture and focal length. They ain't the fastest primes available though - if you consider something like the FA50 - that's a 1.4, but it's not so good until f/2.8 or if being very critical, f/8. The limiteds are very usable from wide open, so in practice, they're faster because there's no need to stop down.
PS: I wouldn't read the comments about money / tripods / kit lenses above as intended to be insulting. I've done paid architectural shoots with my 18-55 lens and a tripod and a circular polarizer and no-one ever complained about image quality. I consider the importance of various technical goodies to getting the shot to be Tripod > Filter > Lighting > Flash > Lens > Camera. It's just that lenses are the most fun.
I agree with your hierarchy of what is important. While I was somewhat annoyed with the original posting, my comments were also intended to be instructional.
I'm an old fart, and I sometimes get fed up with people assuming that buying another lens will bring them results that can only be achieved by getting the basics right. I get even more fed up with people who encourage those assumptions.
I've seen a lot of drivel on various internet forums about lenses that are going to make everything wonderful as well as curing baldness. It gets very, very tiresome after a while.
As someone who has spent a good deal of time helping others learn photography, I don't care much about individual equipment choices. I do care about sticking to the facts and leading people to approaches that will make photography a rich creative experience rather than an exercise in consumerism.
The OP gave the impression that he was completely sucked in by the magical best lens blah blah blah. My comments were intended in part to sharply get his and others' attention and steer the discussion to the real world. Happily that seems to be happening.