UPDATED: 5/20/2011:  I used my D700, and only my 50mm F1.8 to capture my Grandson's first haircut!  I posted an image here.  And, on the way home following the haircut, a clearing storm brought some gorgeous bluish-black clouds at dusk so I swung down towards the river and shot a couple of shots with the 50mm.  I posted one here called "Blue Hour".  Enjoy.  Seriously, can't go wrong -- though the price seems to be creeping upwards...This 50mm 1.8 is an excellent purchase at around a hundred bucks.  I hate to use the word investment, because we know camera equipment is definitely NOT an investment.  I bought it because I heard so much about it, and, I had a 50mm back in my old film days.  I have not  been disappointed.  I will agree with  many here who say that at F1.8 the results are less than stellar.  This is true--- there is a lack of contrast, not necessarily sharpness (at least in my copy of the lens) that you will notice.  Since I know that as a fact going in to a shoot or session, I set my aperture at F2.0, or F2.2 on my D700, or D300.  This solves the problem.  The resulting images at F 2.0 and above are amazingly sharp, and clear.  Don't get me wrong, I love my 16-35F4VR, and my 24-70F2.8 but this 50mm rocks as a standalone lens when the situation demands fast lens.  As a matter of fact, in a few hours I'm heading off to my grandsons first haircut of his life.  What did I pack?  The D700 (for better high ISO performance than the D300), and my 50mm 1.8.For the price (which seems to have risen lately and rightly so) you can't go wrong.  Even if you have other zoom lenses that cover this range as I do, this lens is unbelievably useful in low light to no light situations.  Personally, I'm lazy and hate zooming with my feet, but I'd much rather do that with this lens, than either using flash, or blurring photos of important events.The lens finish is plasticy but so what?  Are you going to be banging it around on a regular basis?  My 50mm travels with me just about everywhere either in a camera bag, or in my North Face Recon backpack (not a camera backpack) just about everywhere, and I pump about 80,000 images a year per body, between landscapes, motorsports, portraits, etc.  So far, so good.  It does stand up to a beating.  I do not use any protective filter on it as the glass is relatively well recessed on this lens.When I do need to use filters such as polarizers, or ND's, I have step-up rings that take the lens from the 52mm size to 77mm which is the standard size of all my filters. It does look "strange" having the tiny little 50mm lens hidden behind a huge 77mm filter, but it WORKS.Again, if you are looking to make an investment -- there's that ugly word again, make that acquisition, to your photo gear you can't go wrong at this price point; If you wind up hating it, there's always the ability to return it, or sell it on eBay.Enjoy. 

Question: How would you describe the texture of the lens at all focal lengths above 150mm?
Answer: this lens is unbelievably useful in low light to no light situations