One of my biggest worries about the premiere of The Winchesters is how good or bad the acting would be. If the actors' acting is bad it really detracts from the enjoyment of a TV series or movie and lately there are a lot of young or newbie actors that just do not know how to act. The story could have potential but if their acting is stilted or unbelievable that can ruin the experience. Thankfully on first watch as soon as the episode started both Mary and John Winchester were acceptable although I do think at times the actress for Mary Winchester (Meg Donnelly) is way more natural than the actor for John Winchester (Drake Rodger). But again it is minor given I have seen worse acting.
Another of my concerns for the series is how fast it would move along. On first look The Winchesters was pretty fast-paced and I think this is great that the series has already set off the type of pace and tone it will follow. Given while it is great to lay out a show's background when you go too slow things can get rather boring fast.
The Winchesters has great pacing and on first watch it has established itself with decent acting with Mary Winchester being the biggest highlight.