I am a frequent passenger of the Sengkang LRT east loop since day 1 (ie way back in 2003). I take it almost everyday.
There was only once when the LRT I was in stopped in the middle of the tracks for like 10 secs? Another one worth mentioning was a LRT train that was controlled by a driver. It was okay but the braking was horrible (cannot blame cos it's human precision

)
In my 2 years, almost 2.5 years of taking the Sengkang LRT, I have not met any glitches that are even worse than the minor ones I had mentioned above. Quite satisfied with the models of the trains in Sengkang LRT. I believe the same of the Punggol LRT as the trains and system are similar and even linked.
Unfortunately, I cannot say the same of Bt Panjang LRT, although it has not experienced any major glitches ever since they changed the signalling system 2 ~ 3 years back.
Just my 2 cents worth.
EDIT: Forgot to add in an extra word.
