Both are great buggy's. I personally would go with an 8ight 1.0 over the D8. Supposidly once of the best racing platforms for a buggy. Havent heard much on the d8's results. In my opinion standard hex hardware is nice to have. Not saying that all people prefer it.
A couple months ago I got a new 8B 1.0 Race Roller for $360 shipped on eBay. I of course already had an 8T 1.0 so that wasn't a hard decision. If you have the cash, these are good times to find a deal on something.