You can thank the UPS strike of a few years ago for this. Prior to that, they shipped everything UPS and you could easily see how long it would take for it to get to you. 5 bus. days max. I'm in MD and ground shipments from OH (where Nashbar is located) would take 2 days. After the strike, they started using USPS for a lot of stuff.
I've been ordering from them for years and have never had a problem, same w/ Performance. I did stop ordering from Supergo (a.k.a. Super Slow) because of repeated problems, being charged the wrong prices and taking many days before the order even shipped.