I've just finished the game with my Renegade Shepard, and I must say, it was amazing. The only issue I had was with importing Shepard's face, and I know many people got this error. Otherwise, it was almost flawless.
I think that Shepard, Ursula, had the best set of choices made in the first two games. So I managed to save most of the people I knew from the previous games, aside from those whose death was unavoidable. There was a couple of moments I just had no information about, but since they were not mentioned in my game, I can pretend they didn't happen. For example, I haven't seen Kelly, so I hope she survived. I'm not ready to write about characters' deaths though, that was heart-breaking, even with those I didn't care much about before. I was close to crying several times during the game. But, to be honest, I laughed aloud much more.
The new characters were decent, though I can't say I really liked them all. I find Javik fascinating and sort of necessary for the game, despite BioWare's claims that he's optional. Vega was kind of meh, I'd gladly replaced him with Steve in my team. Sam was an interesting girl, and I'd probably romance her, but I couldn't find a way to trigger it. I like EDI's new body, especially after putting some armour on it. She has a brilliant personality and a perfect body, no wonder Jeff developed a crush on her.
Talking about crushes, I loved-loved-loved seeing Tali and Garrus together. They make a really sweet couple. I was happy to see that Jacob got a good partner, and they're expecting a baby. My Shepard was not into romance herself (aside from her very close, but strictly platonic, relationship with Liara and one-sided attraction to Ash), but she was happy to see her friends being happy.
I want to play again, this time with one of my Paragons. I'll need to tweak their saves a bit first though. Otherwise, I will really be crying at some point.