Ok, just got the rackets today, have not had a chance to string them yet but here are some measurements.
Tantrum 300: weight 89.2g; balance point = 284.1mm
Visible Hollow 1800: weight 88.2g; balance point = 290.5mm
Lethal 70: weight 87.1g; balance point = 280.2mm
The Tantrum 300 is right on spec for weight (88g - 90g) and is pretty well balanced and almost right on spec (285 +/- 5mm).
The Visible Hollow was the head heaviest and outside spec (285mm +/- 3mm) at 290.5mm. There was no weight spec that I could find.
The Lethal 70 which is supposed to be head heavy has the lowest balance point making it the head lightest of the bunch and way out of spec (290mm +/- 3mm). It was also the lightest racket at 87.1g, spec was 87.5g.
These may just be manufacturing variances but I find it interesting that the Lethal 70, which is marketed as the head heaviest, and therefore the best for attacking smashers, is actually the head lightest out of the three I bought and well outside their spec.
I obviously can't tell which racket will be best for me until I test them but based on the specs of the rackets I received I'd guess the visible hollow will be my personal choice based on the head heaviness.
Once I've had a chance to string and play with the rackets I'll report back again. I plan on stringing them all with BG85 in order to keep everything constant except the racket itself. Since all the rackets were G2 grip will be removing all the original grips and replacing with super grap to keep that a constant too.
I will reweigh and check the balance point again after stringing and regripping.