As much as I love Heyward when I take off my homer glasses his numbers aren't that great. Last year in a full healthy season he hit
.271/.351/.384 with 11 hrs 58 RBI and 20 sb
Other comparable seasons from young defensive outfielders with potential
2008 BJ Upton. .273/.383/.401 with 9 hrs 67 RBIs and 44 sb
2009 BJ Upton .241/.313/.373 with 11 hrs 55 RBI and 42 sb
2013 Dexter Fowler .263/.369/.407 with 12 hrs 42 RBI and 19 sb
I could list a few more but his season was comparable to players like Michael Bourne, Coco Crisp, Brett Gardner, etc. Heyward was my favorite brave but statistically he can easily be replaced for much cheaper. Maybe not defensively but plenty of players can put up better seasons than that.