They are both (and along with Craftsman) made by the same maker.

I posted a similar question (different brands though), see link below. I bought the Echo and have been VERY pleased with it. Starts easy, runs strong. Seemed to be the concensus when I asked to go with Something that did not have EPA restrictions on adjusting the carbs.

Here is a link that might be useful: Link to Weed eater question

had an echo for 10+ years. I use stabil in the the gas and run it dry at year's end. I also change the plug each year...never any issues. I think they also now reccomend and Ethanol additive on these little engines.