How hard was it to solder the ATmega? I'm planning to make a board with an ATmega32U4. But I'm a bit worried about soldering it. I have a decent temperature controlled solder iron with some small tips, solder flux and braid. I'm just a bit worried about solder getting under the pins and connecting them.
No, I have to say that with the finest soldering tip (1/64 or .4mm) and the finest solder wire (.4mm Kester in my case) it's really quite easy to hand solder. That's how I did it the first time. Then I bricked the chip because the crystal was too fast. I removed the microcontroller with a hot hair gun and it left solder very neatly on the pads. The second time I just put flux over the pads, the second microcontroller over that, and applied hot air again and it pretty much sucked it in. So both ways really were pretty easy. Hand-soldering this chip was a lot easier than a 100 pin TQFP Altera CPLD I did a couple of weeks ago, I couldn't hand-solder the pins individually at all and had to use the flood and wick method.
If you have a problem bridging pins, just add a little flux and apply the braid. It really does suck it out even where it can't touch as long as it can touch some of the solder. That is surface tension working for you again.