I have both a TCP202 (w/1103 power supply) and a A6302 (w/AM503 amp). Below is a comparison of the noise levels for a 0 to 2.0mA square wave @ 1MHz using a Keysight MSOX3104A.
The first photo shows the two probes on their most sensitive scale (Ch1 = TCP202, Ch2=A6302). Since the TCP202 has no scale adjustment (fixed 0.1V/A into 50ohms), all the amplification happens inside the scope. As you can see, the TCP202 is pretty much useless for signals that low. Admittedly, much of that noise is from the scope itself since it's on maximum sensitivity (1mV/div), so if you had a low noise front end you could do better. BW limiting to 20MHz just about halves it, so that's another approach.
If your signal permits, you can use averaging for a much cleaner result. The second photo shows a 256 average. However, the TCP202 signal is still too low to be very useful. This particular scope has a "magnify" feature, which can be used to increase the amplitude of the displayed waveform, third photo, magnify in purple. It can be handy if your scope has it too, but it's still pretty noisy.
If you're wanting to measure small signals, I would definitely go for a A6302 before a TCP202. The A503x amplifiers can also be used with the larger A6303 probe for even higher current measuring capability.
I also have the adapter that allows me to plug the TCP202 directly into the Keysight scope, so truth be told, I actually end up using the TCP202 most often because of the convenience factor. The Rigol T2R1000 adapter lists the TCP202 as supported, so one would presume they've done the design and testing to meet the power requirements for the list of supported probes.
If you're looking to buy a used TCP202 or A6302, make sure you get one where the housing is not cracked around the core closure (or pieces missing, I have seen). It can prevent proper seating between the core halves and ruin your measurements.
I've also used the i-Prober 520 and I agree with other posters that it's far too fidgety and, I would add, limited in bandwidth for use as a general purpose current probe. I wouldn't go there.