Marksman AEG's are very complex and require experience to maintain or the resources such as a tech that works near by or having the $moola$ to ship it to a large store such as ASGI.
However a DMR AEG gives you more options than a spring rifle. Im a AEG person, have been ever since I have started playing airsoft. They give you a overall advantage at close ranges. Ecen some stock AEGs match spring snipers...or in this case a brand new BAR 10 and Full length M16. The BAR 10 using a .30 g bb, the M16 a .25-.28 g bb should have comparable accuracy given correct hop up, bucking, barrel combo.
If you just want to better yourself as a airsoft marksman and already have a few AEG's then I say get the springer. If your just starting off, don't focus on demanding roles such as marksman. For the time being work on your basics with a well built AEG, excercise more advance tactics and have a feel for different replica bases like a SAW or even CQB guns depending on your area.