I have never seen a Lactaid for sale except online, so I've never seen one or used it. The hospital I gave birth at has lactation consultants who basically gave me a free SNS to use. I hear people say they like Lactaid better for various reasons, but it's not cheap, so I didn't want to throw more money at the problem. It's kinda fiddly/tricky at first, but you get used to it. The cool thing is you can order SNS stuff real cheap on Amazon, so when you're already a bit frantic trying to deal with newborns and breastfeeding issues, it means you don't even have to leave your house and drive all over town tracking this stuff down.
I used SNS with both kids until they could switch back and forth between breast/bottle, which was around the 2 month mark.