If you look at my review for the XT6 I gave that instrument 5 stars but cautioned readers not to buy it. At that time I said that, given a chance, I might jump up to an XT8. I got the chance, and I grabbed it. Here is what I learned.
The 6 has a slightly longer focal length. This means that if your main purpose for viewing is to see object within our solar system, i.e. planets, moon, etc. It won't make much difference which scope you purchase. the 6" is cheaper and lighter. Solar system objects are bright and look good at about 200X, which either scope can deliver on a good night and neither can deliver on a bad night.
But I don't look mainly at solar system objects. I like to look at deep sky objects, like nebula, galaxies, double stars, etc. For these, the more aperture, the better. 8" is notably more aperture than 6". It is true that the 8" weighs more than the 6. I am 52 years old. I can lug either around my yard, but I added a cart for the 8". My yard is nearly an acre and I would rather pull it around than carry it. In my earlier review I said that I might keep my XT6 as a travel scope. That wasn't necessary. The 8" is easy take apart, place in its bag, and carry to other locations. The bag is necessary for travel. I did keep my 6". I began teaching seminars and now have 5 scopes. I regularly use reflectors, refractors, composites, EQ mounts, alt./az. mounts, and dobsonians. The XT8 is my favorite. I think I'll keep this one for awhile.
I've tried the goto scopes. They are handy, but given the choice of spending my money on electronics or aperture, I'll go with the aperture. I have some scopes with EQ mounts. Given the choice of spending my money on a fancy mount or aperture, I'll take aperture and the simple dobsonian mount. EQ mounts are only necessary for photography. This scope is about as big as an inexpensive portable scope gets and about as small as a serious visual scope gets. It is a great beginning and intermediate scope.