Efficient to level as shadow?

Hey all,
I played a hunter in Vanilla so levelling a priest is new to me. Currently I've been doing PW:S->Mind Blast->SW:P->Wand till dead. This has been working well for me so far but I'm worried about the future, I've gone 5 points into Spirit Tap (God bless) and will probably go 5 points into wand damage and then start filling out my Shadow tree. I was wondering if I'm screwing myself by not levelling as Holy because people have said that Shadow isn't very good until 40+. I'd appreciate any tips you can give me and let me know if my strategy for talents while levelling is super inefficient. Thanks!
I played a hunter in Vanilla so levelling a priest is new to me. Currently I've been doing PW:S->Mind Blast->SW:P->Wand till dead. This has been working well for me so far but I'm worried about the future, I've gone 5 points into Spirit Tap (God bless) and will probably go 5 points into wand damage and then start filling out my Shadow tree. I was wondering if I'm screwing myself by not levelling as Holy because people have said that Shadow isn't very good until 40+. I'd appreciate any tips you can give me and let me know if my strategy for talents while levelling is super inefficient. Thanks!