As far as I'm aware, TmX is the only real server still having DDoS issues atm? EKT seems to have adjusted much of their DDoS mitigation so that it's significantly more effective now (the attacker is apparently trying different types of attacks as a result), and CT also has fine mitigation in effect now. As I look at the launcher right now, I see that there are 3 servers populated -- one being CT, and the other two being EKT. At the current population levels, 3 active servers are honestly enough for the time being. It'd certainly be beneficial for TmX to get some tweak their mitigation a bit, especially if they plan to promote their server, though higher-end mitigation isn't critical/required per-se. That said, 10 euros/month isn't bad at all, and should be fairly easy for TmX to accomplish.
I'll be honest though, I haven't been on as much for the past few weeks, so I'm basing most of my information off of conversations with community owners/members rather than in-game experiences.