I waited with leveling most of my alts because BFA leveling is boring (IMO). But when heirlooms released i bought them instandly upgraded all sets cloth,leather,mail and plate. After i started leveling my rogue i found out how untuned the heirlooms really are compared to the normal gear you get.
First of all you dont get any mastery from your heirlooms or versatility. The stats you get from your heirlooms are way to low for the price you pay for them and you are really squishy aswell with heirlooms if i pull 3 mobs on my outlaw rogue i can die easily and i have leveled trough these zones before on my other characters without heirlooms and i never had this issue before.
Any of you have been experiencing this unfair balancing of heirlooms and any tips for someone who just want to level fast with heirlooms and doing quest quickly instead of pulling just 1 mob at a time.