I second Michael comments, this is king of man to man massage places in Thailand. Selection method not as intimidating as in places where boys are too close to comfort of some , here glass wall and usually few other clients in the lobby and no pressure from mamasan puts you at ease. Plenty boys available, most on manly, muscular side. VIP room looks like hotel room with all comforts.
Boy will shower with you before and after massage.
If you can't decide you can have meal or drink in restaurant with good view at the glassed enclosure and boys inside.
Although there's conventional wisdom one should not have a meals right before massage.
Not difficult to find , keep going up to soi 11, when it forks , take left fork and keep going-there's neon sign at end of soi on your left .
Any motorsai driver at mouth of soi 11 knows the place but its nice walk as soi is pretty busy. If you get lost there's Banana Club on your way.
Being big fan of massages can't imagine being in BKK and not visiting place at least once unless you like being massaged by skinny but cut twinks -stay in Silom for that.