NEW Flashback 2 X4 Delay | TC Electronic | Demo | Review 

I love these guys, please keep the videos coming.

Is it normal that when changing presets some delays don't immediately work?

A real drawback is the fact that you can't make a preset with two independent delays in series. For example, I like to use an extremely short delay to fatten the tone, followed by a dotted eights note delay with modulation. The pedal has by far enough processing power to do that, it's a limitation that could be fixed with a software update. But that will never happen in this company.