I have used both Hornady and LApua in a 6.5-284 and maybe I just got a good lot of Hornady stuff, but my accuracy is identical and it has lasted as long as the Lapua did for me. I can get sub half inch with it. If I were competing I would just go ahead and buy the Lapua, but for hunting, no need. Stay away from Winchester 284 brass. that stuff SUCKS!!! Seriously, it sucks.
I buy only Lapua or Norma brass if available. Yes, its expensive but in the long run is worth it. One bonus - very little prep is needed and it lasts much longer. I never considered buying Hornady brass because I have read too many negatives about it. Many shooters say it is too soft and splits easily.