Not sure what Alex rims you're looking at specifically, if they're eyeleted with a nice seam there won't be much difference. But, in my experience between cheap and nicer rims of the same style (box or v) the difference comes in weight and holding true. Nicer rims also will likely have a better junction at the seam, helping aid in overall wheel longevity. If you're going with 32 or 36 spokes, and don't care about weight, it might not be worth the extra investment, but it would probably be worth asking the advice of your LBS who builds a ton of wheels and the maintains even more.