I dunno, I disagree with several of the things posted here, which I've seen posted several times. I don't think LD shafts are a "gimmick"; they're a natural progression of the technology of the game. Remember, tires used to be made of solid rubber, now they're radial. (Yes, I know that some tires are still solid rubber even today, but you get my point.) And forget the "I passed the plateau" remarks; as stated, just about every pro out there uses LD shafts. If there really were a "plateau" that LD shafts had (and consequently, non-LD shafts do not, for whatever reason you think), wouldn't those people also be switching back to solid maple shafts to play with? Maybe they would...or maybe, just maybe, LD shafts are better. Yes, if you have a straight stroke, you'll shoot well. If you have a straight stroke AND an LD shaft, you'll (probably) shoot better than with a non-LD shaft. Welcome to the 21st century. Older is not always better (think rails, felt, balls...do you really want to shoot with clay balls?)
Seems like common sense to me.
As has been said, no matter what, any new cue will take getting used to. Even Efren has said that when he was shooting with a new cue, he needed to get used to the feel of it. We all know how well he can shoot. If HE needs to "get used to" a new cue, what makes you think you wouldn't? We can't all be great, and certainly, we can't all be Buddy Hall. He's not call "the Rifleman" for nothing. But I bet Budy, Efren, or a dozen other pros could pick up a house cue and beat 99% of the people on this board, or in the world for that matter. The fact that Buddy could buy a new cue and win a tournament with it, no matter how many times in a row, isn't a good example of anything other than "it's the indian not the arrow" (which is true IMO.) For us mere mortals, we need to get used to our equipment. If you don't need to...you probably should be playing on the pro circuit.
FWIW, I don't think my LD shaft "masks" any problems I have. I still shoot like crap, make stupid mistakes, and get lucky sometimes. But you know what? That corner pocket bank I made last night? I called it, and I could do it with my non-LD-standard-maple shaft, and I can still do it with my LD shaft. I've left my cue at home and played with a house cue on more than one occassion. I still shoot the same, still make the same shots, and still miss the same ones I miss with my high-dollar cue equipped with an LD shaft. At least I'm consistent.
I think the bottom line is this: shoot with what you like. If your goal is to pick up any stick and shoot well, all you need to do is practice your stroke. For the next 10 years, probably. LD shafts are great, they do help a small bit, but in the end, all that matters is your stroke.