When I started out buying firearms I really wanted an MP5, I knew they'd be expensive etc. and I just assumed there would be one that wasnt full auto ( obviously I didnt know anything about firearms etc)
Then I see there is no MP5 9mm HK semi auto etc. but there is a 22LR one and I got all amped up really wanted one. Several different boards I was reading dissuaded me (others as well) from the MP5 one (I guess the "better" one has been discontinued, now there is an "official" one that isn't as good?) and said the best would be the S&W M&P 15-22, I really wasnt so sure I wanted it but everyone raved so I bought it...
Now I love it so much I have spent about $350 in Magpul accessories AND added an Aimpoint Micro R-1 for it. It's amazing, addictive, fun, accurate, reliable, dead nails quick and handling like an AR etc. It cycles Federal Bulk, it works more accurate with say AutoMatch, and it snipes with Mini Mags, it just gets better every time I play with it... I say play, it is the closest thing your money gets you to just acting like a DevGru lol. Pure fun.
Part of me would still like the MP5, It looks so cool. But my S&W M&P 15-22 , plus I have a Remington 597 sporter (hooked up) and a Savage Mark II GXP, I have 3 .22LRs to keep me occupied. The MP5 (and SIG for thast matter) are nice, but expensive and I just chose a different direction,