MOSFET

some are better than others, but they rule. always have.

Kind of no brainer if you want good performance, reliability and high power.

There is no perfect device. Mosfets output stages are:

- more robust than transistors
- have higher bandwidth
- are more tolerant of difficult loads

but are:

- less efficient since have lower voltage swing from the same supply voltage
- are more nonlinear than transistors around cutoff region
- require more gain in preceding stages to eliminate crossover distortions
- limited ability to apply local feedback (low gain)

My experience with different types of amps is very limited but judging by reviews and opinions there are good and bad amps in each category.

The only area where Mosfets win hands down are class D amps but this is different type of Mosfets (vertical vs lateral) specifically designed for switching.

To continue and correcting Kijanki, especially nowdays, bipolar transistors are substantially higher quality than a couple of decades ago. Hence most of advantages/disadvantages of bipolar transistors vs. MOSFETs disappear (especially for audio applications) such as
- higher bandwidth(no need to go onto MHz ranges I believe)
- more tolerant of difficult loads (never had been more tolerant than bipolar transistors that have substantially lower output impedance with common emitter connection)

Therefore the preference to MOSFET based power amplifier could only be for older vintage models.