I have only tried the DA a few times, for obvious reasons.
Flying the edges of the furball area is at best only moderately effective. You can get pure 1v1s there, but only if they are quick. If you find that even matchup that results in an extended engagement that an apparently dwindling part of the population is looking for, be assured that somebody is inbound to spoil it.
The times I have asked on 200 for somebody to meet me at an outlying field have only resulted in silence. Just upping from an outlying field is a complete waste of time.
My solution is to log in MW, change countries to the one with the lowest numbers, find the closest enemy airfield with active dar, up whatever plane I am working on at the time and go buzz around the dar ring at 5K agl. If nobody shows, I whine on 200 about the milkrunner at the base I am at. The results are a 50% chance of burning my 40 minutes of fuel up (P-40E 50% +DT) and going home bored, a 30% chance of the bardar lighting up and dodging the subsequent HOs from the Hurri and 110 tag team while the Spit closes in for the kill, or a 20% chance of getting my fight. That sounds like bad odds, but once I find the fight I can usually keep returning. The offer of easy kills may be what keeps them interested though, I can't be sure. This lasts until my opponent gets bored or I come back from getting a drink and the war has caught up to my autoclimb.
The benefit of an arena is that you can always go do something else for a while to keep things interesting, like support the war, up an osti or roll some bombers.
The TA is good up to a point, but without the penalty of awarding a kill and having to re-up again, the fights can not get as intense. You also cannot learn how to fight with a partially damaged aircraft.