I decided about 4 months ago to shop for an "instant read" thermometer, after researching just what that meant. For the MK4, that's 2-3 seconds. I finally stumbled on this little gem, a LavaTools P12 Javelin, available on Amazon for $25.
Lavatools PT12 Javelin Digital Instant Read Meat Thermometer
It reads "instantly" in 3-4 seconds, well into my acceptable range for 1/4 the cost of the MK4. Besides, if it didn't work that great, I would have just sent it back. No bells and whistles. No backlight (I don't smoke without a light on), display doesn't rotate (I can read upside down), and comes in about 6 colors (I like red because I can find it no matter where I lay it down). Added bonus is the magnet on the back to stick it to my pellet box between temp checks. If you're on the fence about buying one, and you're a Prime member, you can have one in 2 days, try it, then return it if you don't agree with my assessment.