Only ti-goat products that I have are the omni raven and ptarmigan bivy. With that said good products. I do have the seek outside 6 man tip with all the bells and whistles. Absolutely no complaints, very well made.
I don't own any of them, but have spent hours on all of their websites, read plenty of feedback regarding all of them, and don't recall reading anything bad about any of them. I don't think you can make a wrong choice here, so for me, it would probably come down to the most bang for the buck.
I've run the 7.5 for two seasons and have used it for summer camping also. It has been stellar. The 7.5 is a mansion for two and your gear...even with a stove. The 8.0 is overkill unless you're truck-camping/using cots or have a larger group. I dealt with Josh through emails and he's been great. I asked to swtch to cubin fiber and he agreed to make the tent for me. Saved about half the weight! Last season I bivied away from the tent two nights and a squirel/mouse surically removed one of the guy-out lines. No problem sending it in for repairs-great customer service.