I have a Cort X6-SM which is grossly neck heavy. While standing up i always had my left hand support the neck or later hold the guitar too-high and pressing in with the right elbow. Even with a 3" Nylon strap the guitar would gradually want to kiss the ground. To get rid of this i ordered a HeadsUp Guitar Strap on 23rd May from ebay ($56: $40 + $16 Shipping) and i received it today. Given that the item left NY on 9th June i guess that's pretty fast by IndiaPost Standards.
Coming to the strap, its pretty much like my Levy's 3" Nylon Strap in quality except that the body end has a pocket (along the length) which holds 3 lead weights to counter balance the heavy neck. Even though a sticker on it said most guitars need 1or 2 of these, i ended up using all three to just balance the guitar. The pocket has a velcro to secure the opening, though i have added few layers of clear tape on top of it to make sure it does not fall while transporting. The pocket opens away from ground so while standing up there is no chance of the weights crashing down unless someone does a somersault.
The strap does what it says, pretty well. Except for getting rid of my habit of pressing with my elbow i feel very relaxed playing standing up now. With the left hand now not countering the weight I also noticed an improvement in moving around the neck. Although i still hold the guitar high is i am comfortable with the position it is still about few inches less and at an angle so that i have a better view/access of the lower frets
If you have a neck heavy guitar, trust me this is one purchase you won't regret ever.