I really depends on how you are switching channels. I have never used the stock pedal before, so on that I can't really comment. My VOX multi-effects MIDI pedal had noticeable lag when I ran the guitar through it into the JMD. My new
setup has cut the lag time and is almost or not noticeable. If you have the stock setup, I can say that lagged switching is a known issue with some users of the TSL. To a lesser extent the JVM410, the JVMHJS has somewhat faster switching than its brother. In some of the designs there are noticeable clicks or pops when changing channels, so they delay the switching to minimize the effect.
This lagged switching is a serious bone of contention with me. I have owned a TSL100 since December and it has been sitting on the work bench ever since because of it. I hope to get it modded out before next spring. I can't understand why Marshall puts band aids on designs instead of fixing it at the source. I am assuming it is a R and D money issue. I have owned a Original ValveState since '92 or so and I never had an issue with it, switching wise.