It is believed that 1.4 BD is slightly more numbing and less high properties than GHB / GBL and also toxic for your liver....
I try to stay away from 1.4 so I have never actually experienced it, but I believe i have read that 1.4 gets "chunky" when put in the fridge
Lately I noticed a lot of people sell mixtures of GHB / GBL in the clubs, Why?, well the GBL is a lot cheaper, but since the broad public is used to the nasty salty taste of NA-GHB they put some into it. You cannot taste the lactone anymore, but it's easy to detect if you smell the faul acethone fumes of GBL ....
I don't like these mixture, makes it strength and the come-up etc more unpredictable.