Much faster (and almost as bulky in Rillaboom’s case) than the slogfest of the last generation, that’s for sure.
They all have really good Hidden Abilities and a mostly manageable movepool for their fierce offensive prowess, despite having mono-typings this time around.
I like Inteleon for it’s gliding spy motif, even if it is heavily contested by many. It is almost as fast as Greninja and specially offensive as Primarina, which is an awesome sweeping combo a Water-type can have, even if Inteleon is short on good coverage, as Mud Shot is a very niche option.
I actually quite like them! Usually every generation has a starter that I don't like as much as the others and this still holds true with Rillaboom, but I'm pretty happy with all the others and think it's a pretty solid group of starters. Maybe like, above average for me?
I'd say they measure up very well. First monotyped set since generation 2 so that's nice to see, quite specialised and meta-powerful stat-wise for classically more rounded out starters, and each one has a very powerful and useful Hidden Ability (something older sets tend to lack, with only one having a hugely overpowered HA compared to others - think Hoenn and Blaziken or Unova and Serperior). Also, their motifs are so ridiculous and awesome at the same time, and very overtly (and comically) Pokémon-British too.