In all fairness I am open to the idea of LED Christmas lighting IF it's done right. I am intrigued by the true C9 LED's that Louis originally posted about, though not the translucent ones. I never liked the translucent incandescent C9's either. I do wonder about those bulbs and flicker given they appear to be a screw in replacement for regular C9 sets which obviously operate on AC current. So I imagine there must be a power supply crammed into the intermediate base of the C9 bulb.
I would also need the actual light to look as close to incandescent as possible, the softer warmer light is much better on my eyes than what I see from your average LED string that people buy at any big box store.
My biggest complaint with Christmas lights in general is just how cheap garbage the quality is, I truly believe they're meant for one use and to be discarded after, given that's usually how long they last and usually do end up discarded after. Several years ago I ordered a 50 light C9 string from christmaslightsetc, it's a durable string and even the bulbs I originally ordered from them lasted several holiday seasons. I will probably get up to speed on their LED offerings and consider ordering a couple boxes of LED lamps for that strand as I am intrigued by the durability of the lamp assuming it's plastic, also provided it doesn't flicker and looks more like an actual incandescent.
As for LED lighting in general, I believe it has it's time and place. I notice many commercial establishments using LED's now look sterile while they never did using incandescent. At home I use LED's in all the fixtures that see high use and where I desire a long lasting lamp. I'm using up my stockpile of CFL's in the outside fixtures, and incandescent in everything on a dimmer or in fixtures where I want the exact type of light only an incandescent offers.
I'm also seeing some premature failures with LED lamps, namely some earlier model GU19's bought from Lighting Ever on Amazon, and interestingly, the highly revered Cree brand. I've yet to have a failure with any Philips or Osram LED's and Cree has been top notch about sending warranty replacements.