I always found down uncomfortable. I wear typically, standard competitive "speedo" type suits, up works for me best. Or up/angle.

It really depends on the cut of the suit.

The flat front competitive cut swim suits from the likes of Speedo, Arena, TYR, and the like I prefer to be either up or up and to the side. There just is no room in those suits for doing anything else as they are smashing everything down to make the smallest possible profile.

I much prefer suits with a pouch built in like the Speedo Solar and other suits available from an array of other small manufacturers like Cocksox, N2N, Covermale, and others that have pouches ranging from small to absurd depending on how much you want to show off. In this case, with a nice pouch, going down and forward is certainly the most comfortable.

I highly recommend trying different methods with your favorite suits and you will quickly figure out what is most comfortable with one may not be the most comfortable with another. You can't just slap a single label on it, different styles require different situations.

Well said MrMusik

It is clear that contour pouch with a central seam is much more comfortable. It takes male anatomy into account.
I have some briefs like this, and I observed that when I position my penis downward it is much more visible.
Being circumcised you really can see every detail, mostly with bright colors and when it is wet. Briefs with spandex are very revealing too.
So in public pools you have to keep that in mind. I can't hide my anatomy, but I don't care now.

I think age and confidence are part of positioning choice. When I was younger, I always positioned down, making a nice rounded bulge. Most of the guys on my swim team did the same. If I did get hard, it was not quite as obvious, the bulge just looked bigger. As I got older I shifted to positioning up. I hated the feeling of my penis curving down between my legs, it just feels more comfortable straight upward. If I get hard, I just push sideways as needed.

In really cold water, physiology makes the choice for me: straight ahead. :)

Doesn't really matter! Which ever way there isn't much left to the imagination! Shaft, veins and head all well displayed. For me i prefer down and to the left i guess for max bulge otherwise it tends to shrink back if pointed up and does so after swimming anyway

Most designer suits have built some space for bulge and I believe putting downwards is the way to go. I usually wear competitive style suits without front contour, I will point upwards and if the suit is unlined, that can be very sexy.

Another approach to the bulge!
 

I have the M73 Rio microbikini from Skinz, and I like to wear it straight across, as low as possible in the front, for full abdominal exposure. (The top front edge rests right on top of my shaft; being a Rio, there is a "cheek-and-cleavage show" in the back;) !) I do a complete bodyshave, so no pubic hair. I have ab-muscle definition fro bottom of pecs to shaft, with a definite arch of muscle over the shaft. The Rio pouch only allows a downward placement of the shaft, but that is what I prefer, and it is comfortable. When I'm flaccid, the pouch is pulled down slightly, exposing the smooth, tanned top of my shaft. If I'm erect, the pouch hangs even lower, exposing more of the shaft and my tiny tan lines :eek: (For me::D :D )

Sounds HOT microbikinidave
We need a picture Please
Thanks