I've heard some pretty bad things about Portable Ops... like the crappy camera and controls... but I really liked Peace Walker, and moreover, I really like the character of Big Boss, more so than Solid Snake...
I played other MGS games like the Gameboy Color one, Ghost Babel, the original MSX Metal Gear, and the first MGS... but I've been holding out on Portable Ops... I'd really rather not buy something that I wouldn't enjoy... and I really DO NOT enjoy games with bad cameras and bad controls...
I had my doubts about Portable Ops too, but I was surprised that it wasn't as bad as people say it is. The default controls suck, but you can customize them(I customized the controls so they were similar to PW's shooter control scheme)
The story isn't that great when compared to other games in the series, but it's still okay. You should at least try it out and you could always sell it if you don't like it.
"Not happy about that? Get over it." -Solid Snake (MGS2) April 23, 2011 - Anthrax, Megadeth, Slayer, Metallica - BEST CONCERT EVER!
Yeah, I'd say give this game a try but keep in mind that it will be inferior to Peace Walker overall except for perhaps technology consistent with the Metal Gear timeline. Oh, and if you like Big Boss you NEED to play Metal Gear Solid 3 in some shape or form. Let me stress that, NEED. The Subsistence version is recommended like the other guy said due to the better camera control. Oh, and if you are lucky to get a copy with the second disk you can get some really neat bonuses, including tweaked versions of the original Metal Gear and Metal Gear 2: Solid Snake. I also recommend the latter due to it being one of my favorite 8-bit games.
I don't see what the gripe is with this game's controls. Its default configuration has worked just fine for me for years now. I never had any problems. I realize taste in controls varies and depends solely on the player's style, but it just seems too easy to be annoying.
Yes, get this game. If you're anything like me, it'll keep you playing for years to come.