The most valuable time in DCS for me has been in the L-39 with someone in the back and front seat. That includes awesome Red Flag missions with the 104th, many Blue Flag hours, training with the squadron and single player. Flying as a crew seems to be the most fun not only IRL but also in the sim. While the L-39 is a great airplane and trainer, in my opinion we could benefit from a trainer with modern western avionics, if it can do FAC(A) and other mission even better.