You can preorder for store pickup online as well. In general, while I've never had issues with Best Buy mailing me my product, I tend to recommend store pickup and doing it through the website. I work at a Best Buy location and deal with a lot of the preorders and there's only a single time in my couple of years working in the back where my location has ever been unable to fulfill a preorder, and that was solely because we were never sent a single copy of the Xbox version of that title (which I think we only ever received three of total for PS). Outside that, we've never had any issues fulfilling any orders since from personal experience, our website is very reliable at actually preventing preorders from exceeding allocated inventory amounts (unlike Amazon's website).

The only small reason why I personally recommend online as being more reliable is simply how the preorders are managed in our system. Inventory is still properly allocated and reserved regardless of which way you do it, but the way online orders are processed is a bit more automatic while there's an extra manual step on our end for in-store orders. It's not a big deal, but if you're trying to be risk averse for peace-of-mind purposes, it's something worth considering. Personally, I find preordering through our website to be easier and much faster than doing it at a register anyway. :p