I think the PIO state machines are pretty cool and relatively unique. I am also glad the Foundation resisted the temptation to market them as extra cores and sell the RP2040 as 10-core processor.
When it comes to the Raspi Pico and similar devices[1], I think UF2 flashing is the best thing since sliced bread.
This alone lowers the barrier for beginners significantly.
Things I don't like: power consumption.
But you can't have everything...
[1] I know it is not restricted to RP2040 boards, but I think it is nowhere as common as there.
RP2040's full-speed is okay. 20+mA is a lot but it is easily explained by the absurdly huge SRAM banks it has.
But RP2040's sleep states are absolutely AWFUL. The Cortex-M0+ chips are all extremely power-competitive vs each other, because Cortex-M0+ is extremely low-end with regards to core-design.
You're pretty much only getting a Cortex-M0+ because its the absolute minimum 32-bit processor on the market. (8-bitters and 4-bitters exist if you're willing to go even lower-end, but Cortex-M0+ is the bottom of ARM's offerings). So low-power seems to be a must in this market, IMO anyway.
If you're willing to use higher amounts of power, you really should get a few more features, like an FPU on the Cortex-M4.
Yes, it's a lot. It will empty a 1000mAh battery in about two days. In sleep states, you'll find it challenging to reach a single month on RP2040 while you can build things with other controllers that would last years on the same battery.
The main issue is that there's no low power sleep mode. There are sleep modes, but they consume tremendous amount of power, so there's no way to build a battery-powered device.
When it comes to the Raspi Pico and similar devices[1], I think UF2 flashing is the best thing since sliced bread. This alone lowers the barrier for beginners significantly.
Things I don't like: power consumption.
But you can't have everything...
[1] I know it is not restricted to RP2040 boards, but I think it is nowhere as common as there.