I don't know if my brother thinks it's an issue but I do think my sister-in-law might. They just switched their daughter from a home-based day care to a more preschool-like setting. I'm not exactly sure why but they mentioned that she was mimicking the 1yo she played with a lot at the old day care. I have to wonder if they think their child is "slow" because she's not speaking like my DD. I don't think they realize that my DD is a bit unusual and that their DD is just fine. It's hard not to compare, though, especially when they're the exact same age (just 3 weeks apart!).
Ironically, I worried our DD was a bit on the slow side when her cousin learned to do things before her: crawling, waving, clapping and her first word. I think my daughter is a perfectionist, though, and wanted to make sure she could do all of those things just right before she tried them. Probably gets that from her mommy <grimace>.