No marker will every be M40 accurate, but there are a lot of factors. Most will agree the most important of which is paint to barrel match. Also quality of paint, velocity, weather, and the quality of the marker itself can be factors. The Etek is a great overall value. IMHO, the best value at that price point, though a lot of nice markers have come out recently in that range.
It sounds like you may also want to consider an ION, which is a good gun and a couple hundred cheaper than an Etek. If you start playing more frequently or more competetively, than an Etek is definitely worth considering.