To get a personal assessment on whether 8X6 is big or huge or not, just go to any good sex shop and look at a realistically looking dildo of a comparable size. Then you will get the answer for yourself. To get an answer from a typical girl's perspective, buy such dildo and do two things: (i) try fitting in into your mouth and see how far it will go without causing a strong gag response (you will know how a typical girl feels performing a BJ on such dick); and (ii) if you are not already at this size, show it to your girlfriend/wife and tell her that you want to run a dildo test on her. Most likely, she will recommend that you treat yourself with your purchase.
The funny thing is that such big dicks look very intimidating to most women and a typical response would be "OMG, this thing will destroy me", but many of them can take them 100% ok, at least girthwise. A typical female vagina is a very accommodating body part.
P.S.: I got a 7.5X6-6.2 dildo toy for my wife for some fun bedroom play and can attest that it looks very impressive. Another toy at 8X5.5 that we have looks pretty pale and insignificant when placed next to the first one. It is girth that largely defines a dick's size perception.