Looks to be making the best of his loan, and Warbotton is generally a very good manager of loaned players. If he's playing every week and flourishing it will do him no harm.
Despite being very pro Dowell I can see both sides of the debate. Most young players won't make it with Everton irrespective of the manager. I don't really understand why Koeman put him in against Genk unless he thinks highly of him though. I don't think he was anywhere near bad enough to warrant being bombed out. I suspect Koeman wanted to keep him on the fringes, but a decent loan offer, from a big championship club with a manager who would play him regularly and give him a role to flourish may have made us reconsider.
As for the player, the reds have a similar talent with Woodburn who I was speaking to one about. They mentioned about Scholes, who Woodburn reminded him of (a young Scholes who played off the front). Rarely did Scholes excel as a striker at youth level, it was Fowler who did with his power and pace. Yet Scholes would have the better career. He only really broke though at around 20 though.
I think you see something similar with Dowell. If he goes on and bosses the championship, plays regularly and is given a free role it's hard to see the experience being bad for him. At the very least it may force Koeman's hand a bit, or if we are being blunt, mean that if we offload Dowell he will get a high calibre of club.
In my ideal world, he gets Forest promoted and comes back to play for Everton next season. However there are few fairy tales in football. Lets see, nice to see him get such praise though.