I own the mojo,mest mk 2, and the dx300. The Mest mk 2 sounds amazing on the dx300. It has great synergy, impact, soundstage for an iem, vocals and about anything else you would want. I like the Dx300 has balanced headphone outputs so you can get a balanced cable with the Mest also. It comes no extra cost with the Mest. If you do get the Mest mk 2 order from musicteck. They are about $200 cheaper than unique melody. Overall I have 0 complaints with either product. I haven't tried amp 12 yet. Personally I find the dx300 to sound much better than the mojo. The dx300 is way more clean sounding. The mojo to me can get a bit congested with certain iem's. I use the mojo, lcd x , and dx300 together and I like the combination mainly because the mojo gives the lcd x more power. I'm really looking forward to the amp 12 because if it can give my lcd x the sound of the dx300 with enough power it will be a homerun. I personally prefer the dx300 over stacking with mojo and phone due to convenience. Stacks can be a bit much. The dx300 isn't nearly as clunky as carrying a stack around. Also it's nice to have my phone free. I think the dx300 is amazing and would refer it in a heartbeat along with the Mest mk 2. I am like you and can't demo anything. I have to rely on reviews. I understand your worry. Hope this helps. Let me know if you have anymore questions.