That's good advice - I'd take it one step further and say just buy both and figure out which you like better. I have accumulated so many stems over the years in various lengths and rises and it really helps when setting up a new ride. If you don't get too worried about weight, you can find them truly dirt cheap on ebay, and have the luxury of logging enough saddle time with them on the bike to really make a good decision. Then once you have it dialed, you can pony up for something a little swankier if it suits ya.