I first bought a Lumia 1320 for my mom in November. Her phone was dropped in water and she was using my old BB Z10, but it was time to upgrade. She chose the phone herself, she wanted a Lumia 710 when I first got her a phone but said "no, it's Windows, not going to like it". So, long story short, she had android for 3 years and now specifically asked for the 1320. Man, best decision she could have made! After helping her set it up, I wanted to keep it. So after a week I upgraded my Note II, wanted another phablet, went with the 1320. Good price and size, perfect intro to WP. All I can say is if the cameras were just slightly better, this phone would be perfect! Screen is nice, but 720p is slightly low for 6", not a huge downer but definitely noticeable with text. I've had no lag yet. YouTube sometimes gives a decoding error but otherwise is good, the huge screen is perfect for gaming and watching videos. As for apps, well I own Android, BB10 and iOS, so I'm used to having apps and not having apps. The games I have gotten run smooth and work great. Candy Crush has some lag but I only use it to send lives to my gf, so meh. My favorite games are the Mario Bros and Pokemon games and they run great. Also Six Guns, Riptide GP 2 and Into the Dead.
Battery life is awesome, I can get 2 full days of medium to heavy usage, which is all between Facebook, Twitter, YouTube, Instagram, web browsing (CrackBerry.com since there is no app for it) and my 3 personal emails. Same usage as on my Moto X, BlackBerry Q10 and Note II. My old iPhone5s had to be charged twice in a day. The X and Q10 last a day and the Note II lasts about the same as the 1320.
To finish off my "quick" review, I recommend this as a great daily driver, a perfect intro to WP and a good phablet for heavy users. Battery is awesome and its smooth too. Cameras are the main downside. I'll be looking to buy a high end Lumia for a better camera but definitely sticking to Windows for now! Oh and speaker is ok for me, I just try not to cover it while playing music.