Because the only differences between the S8 and S8+ are the screen and battery sizes (5.8," 3000mAh vs 6.2," 3500mAh) it comes down to personal preference. Like other people have said, the S8 is slightly shorter and narrower than the S7 Edge, while the S8+ is slightly narrower and taller than the S7 Edge, so either version should be find.
Personally, if you have smaller hands (like I do) and/or already struggling with the size of the S7 Edge, then go with the S8. If possible, go to a Best Buy and check out both versions there in their Samsung section. Feeling them in hand will prove to be MUCH more helpful, than anyone's 2 cents on the matter. That's what helped me figure out what color and version of the S8 I wanted to pre-order.
Just saying, even with smaller hands, I didn't have much issue with the larger variant. Heck, took me literally an hour to actually do the pre-order because I had trouble making up mind on which size, haha. XD That, and if you do have a Best Buy near you, do the pre-order there as you can save $50 on the S8, $100 on the S8+. Unless you plan on buying it outright, because you won't get the discount, at least that's what I can tell on their site.
