My $0.02 about the notion of size and preference stated.
Yes, I've had guys of that approximate size and also larger, which is why I can quite safely say that a little less than 8x6 is a comfortable - and probably ideal - size for me.
I know the length of my palm and approximately where on my wrist 8, 9 etc. inches end up. I know how much girth is required before I can't close my hand around it and roughly where my index finger ends up on my thumb for girths less than that.
To date the only man I've ever measured in real terms is SO (at his request), and I know that if I verify his measurements by using only my hands I'm quite close to the real numbers. Obviously - measuring with my hands only will never give exact measurements - but it will sure as heck allow me to judge if the guy is in 6, 7, 8 or 9 territory.
Yes, 8x6 is a large guy by all means. I don't know the exact number of men I've seen naked, with erections that I've touched (not necessarily had sex with though) - but they certainly number well above 100, perhaps even up towards 200, as we're active swingers.
Out of all those guys - getting up to 7 (or the precise length of my palm) is a relatively rare occurence but does happen from time to time (and is always a nice surprise). Getting up above 7 and up towards 8 (or beyond my palm) even more rare - I've seen perhaps 5-10 guys in that size range. Guys that reach further up on my wrist (or up towards 9) I to date count to the whopping number of two out of all those I've touched and seen - which should give you an indication on just how rare those sizes and up are.
Girth follows just about the same pattern. Index to joint on thumb (roughly 4.5) is easy to find. Index to midway between joint and tip of thumb (up towards 5.5) are there, but starting to get more uncommon - don't really have numbers in my head - but guesstimate would be probably below 20-30 of the guys I've seen. Guys where I just put index to tip of thumb (a bit above 6) are about as rare as the guys that count in at 9 and above. I have to date met one man that has been beyond what I can get my hand around - somewhere between 6.5 and 6.75 by eyeballing the distance left between fingertips.
So - there you have my experiences from actual, visual observation and estimated (but still very realistic) measurements. I can with quite great certainty say that yes, I know what roughly 8x6 looks and feels like, and I know it's a size that I personally would prefer and be comfortable with. Also keep in mind that preferences given by women on this site tends to be on the higher end of the scale as most of us here have a preference for big.