My $0.02: I'm pretty experienced assembler/C/C++ embedded developer, I was on a very short schedule and no experience with ATmega. I found the Arduino environment extremely easy, and the forum very helpful. That's where I discovered that I needed the SoftSerial lib for my app. I did look at AtmelStudio briefly, but did not see a quick and easy way to bring the SoftSerial lib over, and Arduino IDE was working pretty well. I learned to debug with print f's about 100 years ago, so the serial monitor was like old home week, did everything I needed. YMMV 