I have a sektor on my older (2012) Santa Cruz Heckler. Its a 26" but it does just fine. No it wont be like riding a new Lyrik or Pike, but for the average Joe or those on a budget it will work just fine.
My son still rides my old bike in Bike Parks and a lot of Enduro trails and it does just fine for him. It really depends on expectations , budget and riding style.
I've been rocking one for a couple of years now! To be fair, this was my first real build and I was admittedly on a budget, but it does the job! I've taken it to Copper Harbor and Pisgah and it has handled big mountain rides just fine. I really want a Yari, but it can wait for my next bike. Cheers!