Personally I think they had their time and while they are still cool especially since you can still occasionally find civi-legal select fire models for about $16,000 it would be a fun little full auto toy if you could afford it. But yeah today there are so many other cool SMGs on the market that the MP5 seems old and outdated. But that doesn't mean it's an obsolete firearm by any means. The MP5 is still used by many forces around the world in many different model variations. I could have picked up one of the smaller semi-auto pistol versions some years ago for a little over $3k. Even now there is a new .22 semi-auto version available for some fun plinking called the GSG-5.
The main reason why this deserves to be a Shooter Saturday feature even though it old and there are better things out there is because if there was no MP5 there wouldn't be the other guns. The MP5 is simply a great gun that is easy to shoot, easy to maintain, light weight, accurate and easily customizable for many different rolls. It has been around for a while and it'll be around for a while longer. If I had the cash I'd have picked up one of the class III versions, heck I'd just like to give one a go for a little bit. Try out that HK slap, which honestly doesn't ever make any since to me why they do that in the movies since that notch at the back of the bolt action is the bolt hold for cleaning and what not. Anyways let check out an awesome video of MP5s in action.
