Personally I don't like the Measure Up stuff at all. I hate their interface, their questions are not worded very well to prepare you properly.
Now the Transcender is a totally different story. I find the Transcender questions along with the interface make you feel like your in the real thing. I would overwhelmingly say that Transcender mops the floor with Measure Up.
New Horizons forces me to take the Measure Up and get a 90 or better grade!
The thing is the Measure is crap, In the A+ and N+, those Measure Up questions didnt prepare me for nothing. None of those questions were like the real exam. Those Measure Up questions were like 3 to 4 times harder than the real questions of the A+ and N+.
It slows me down big time. It slowed me down with the 70-210 test. They questions were a little more similiar but that was because mainly the 70-210 was much harder than A+ and N+. Still most of the questions werent anything like Microsoft's 70-210 test. I had to review the material that was more similiar to the real test again so I can have a shot at passing.