Click on the link to compare all the sergers Babylock offers. I only know that my EZ Lock serger from Sewing With Nancy (Nancy Ziemen) works fantastic (similar to the Lauren and not complicated), except I sure would like the air threading system featured in the higher end Babylocks. Sergers aren't complicated at all, takes practice just like anything else. Babylock has step by step directions on their site and serger tutorials are all over the internet. I wouldn't leave the shop without demonstrations, instructions, and free classes with purchase.
http://babylock.com/sergers/compare/