The TCP202 is DC coupled, and the P6021 is AC coupled.
I have used current probes quite a bit for switching power supply design. The DC coupling is critical for this work.
My preference for a 20 Amp probe is an A6302 with an AM503B amplifier. The amplifier provides a lot of flexibility in setting up the gain and offset. Another advantage is is can be connected to other brand of oscilloscopes or data acquisition equipment, since it has a standard BNC output.
I also have a TCP202. I like the size, but the offset adjustment is very touchy, and it relies on the oscilloscope input for AC coupling and gain settings. It is also only rating at 15A rather than 20.
There is a modern replacement of the A6302/AM503B combination TCP305A w/ TCPA300. I've used it at a clients lab, and it is very capable, but very expensive.