I think it may depend on the territory really. I know a lot of times when we are searching to fill engineering positions, we go to LinkedIn first rather than making an ad and waiting for resumes to come in. I think LI is a great resource that allows quick & easy communication and also lets you put much more information about yourself and past projects. You can also get some good recommendations from others you've worked with and have that info posted right to your profile. Which saves time trying to track down that information by other means. I probably sound like I work in marketing for LI but my experiences with it have all been positive.
I used to just have a very plain page for my profile. I've now updated and tailored it pretty nicely complete with a professional picture. After doing that, I get daily emails with engineering job opportunities. Probably at least 3-4 phone calls too. It's not a bad thing to have nicely developed LI page IMO.