JRC STI 2 Man Twin Skin Vs JRC STI-R Bivvy

I'm in the market for a new bivvy & have narrowed my choices to either the JRC STI 2 Man Twin Skin @ £180-190 or the JRC STI-R Bivvy @ £210.

As far as I can tell they're both made from the same materials, both have taped seams, heavy duty ground sheet, pegs etc. In hruth they're so similar im not really sure what the differences are!!

I know the STi-R has adjustable height/width but is that about the only difference?

Any help, advice, suggestions would be greatly appreciated.

Nathan ,take a look at blunderers thread about crap tackle people have bought ,that bivvy is on there .just a thought.

hi there first of all bud the sti twin skin is what it says u have to use it as a twin skin all the time as the inner skin has 4 big mesh panels which are excellent for ventillation and you get next to no condensation where as the sti-r is a single skin bivvy with an optional outer if you want to use one in my opion both are an excellent bivvy but i would go for the sti with the 10.000 material by the way dont pay that much for one they are only 159quid at climax tackle hope this helps a little cheers

Thanks for the advice - they bothseemed to be so similar i couldn't work out which was the better purchase