All conditions considered, I think I probably spend somewhat more time fishing downstream for SMBs while wading. This would esp be true on larger waterways where longer casts are the norm. Since I spend a lot of time searching, I'm usually throwing large streamers long distances. With poppers, even if I'm wading downstream, I'll often throw up and across. On smaller trout sized creeks, I'm more likely to bass fish upstream due to the same advantages afforded upstream trout fishing.