Well, my donut has been treating me well (and me it) for a little over a month now. VTC mini is a perfect mod (the Vtwo mini too, which is just the updated FW and comes with a silicon sleeve)... catching up on the posts here. Been using 255 TCR, 12 watts, and 390 degrees F with great success. Totally portable and stealthy. I've used this on a road / camping trip with amazing results. Gonna experiment with a lower M value, 245 ish, and higher watts, 12.5 probably. The reason being, I was getting a lot of splatter, melting, and just not efficient hits (on the road). This was mostly because I was unable to keep the ATTY as clean - being on the road, trying to be stealthy... The crust/buildup was manageable, but I know I wasted a good bit. Now that I have a feel for the heating/vaporization properties of this device, I believe I need a little bit more of a one-load, one-hit, or at least a more rapid vaporization (power) if its a bigger load, so that its not just melting... (rambling stops here)
For the any person with a donut not being detected - I had a similar experience my first time cleaning a donut... I must've rotated the donut when using a Q tip. My solution: rotate/spin the Q tip the other direction. One of the leads must've been loose. Been a solid donut ever since, with more delicate/precise cleaning. Cheers!