I know this is an old thread and I don't get on here much, but i'll comment anyway.
HH lists the hyperlight as 26oz. The single 1.1 blackbird with line/strap suspension is 20 oz plus my asym-diamond fly (7.5)puts it at 27.5oz
So it looks like the HH is 1.5 oz lighter...that's what HH wants you to think...BUT if you read their hammocks catalogue page, you will see that since their tree straps are "complimentary" they aren't included in the listed weight. They're just trying to make all their stuff "appear" lighter than it actually is (IMO). HH doesn't even list the weight of their straps anywhere on their website as far as i can tell, so a customer couldn't even calculate the actual weight if they wanted to. (aside from buying it and weighing it)....shady yes, lighter no.
i'm guessing their straps weigh at least a couple oz, perhaps they're trying to keep it a secret, i don't know. My guess is that the Hyperlight and it's "complimentary" straps weigh at least as much if not a hair more than my setup. It's probably fair to assume they are very very close in weight even though the BB is good up to 6'6" (i've got a happy 6'8" customer), while the hyperlight is rated to nowhere near that, so if you want extra head/foot room at no weight penalty over the hyperlight, consider the BB.
As far as weight limits go, i try to post my weight limits as to what someone will find comfortable. The single layer 1.1 will hold a 600# individual, but i'm not going to rate it at 600#. A 200# individual will experience the same stretch factors in both hammocks (both are 30d ripstop nylon and will have very similar stretch characteristics). If someone is at the upper limit of the hyperlight and finds it comfortable, they will find the single 1.1 Blackbird will support them just as well.