I use whole cones and pellets. I prefer whole cones with one caveat and, that is, they need to come directly from a trusted source on the West Coast (one that also acquires non-US cultivars from trusted sources). I bought a bunch whole cones from Ted at Hop Heaven earlier this year. I am a huge fan of EKG, but Ted only had US Goldings, so I bit the bullet. Man, those hops have made the must authentic British-style beer I have made over the better part of 30 years. I do not know if 2020 was a good year, but every cultivar I purchased from Ted has been off the charts. There is definitely a difference when a beer is finished with whole cones. Pellets may bitter better, but whole cones leave pellets in the dust when it comes to keeping the essential oils intact.
I used to use whole cones exclusively with a false bottom in my kettle. Nothing works as well as whole cones when it comes to producing clear wort, nothing, at least not at the home brewing level, not even whirlpooling. That is one of main reasons why the British invented the hop back and the Peter Austin design employs a type of hop back known as a hop perculator. I am currently using a hop spider with 1520 mesh that I special ordered from Arbor Fab (one has to ask). The holes in 1520 micron mesh are 1.52mm or ~0.060". They do not clog like the typical 300 or even 400 micron mesh spider that is used with pellets. Wort boils right through the spider. I ordered a 6" spider, but an 8" or 10.5" would be even better. Unlike 300 or 400 micron mesh, 1520 micron mesh is easy to clean too. All that is needed is garden hose-level pressure with a nozzle. I plan to eventually have a custom false bottom made for my DBS 6.6-gallon kettle.
There is a major downside to using whole cones exclusively; namely, significant volume loss in beers with high hopping rates. Here is one area where using a 1520 micron mesh spider with whole cones pays off as the spider can be lifted out of the kettle and the hops can be pressed with a large stainless steel spoon to squeeze out wort. I make my knock-out addition with a cloth bag because my hop spider does not fit in the middle of the immersion chiller, the Faucet Flow (a.k.a. the Mantis), I use with my 3-gallon rig.