Ok, so I can't vouch for the longevity of these boots as I've only skied them a handfull of times, that said, they're great so far. I'm 5'9", 120lbs on a heavy day and ski primarily Dynafit Manaslu 169cm with Dynafit ST bindings. I originally bought the Zzeus boots. Coming from a solely alpine background, I was intimidated by the flexibility and light weight of touring boots. After skiing those boots for a season and a half, foot problems led me to a more flexible and lighter boot. In a size 27.0 the TLT 5's save me 1.6lbs PER BOOT. I have been able yo use the TLT 5's without any molding and my only modification was the addition of some Superfeet insoles. This is a HUGE change from the horrible pains my Zzeus' gave me even after two moldings and the addition of insoles.
My first day on the TLT 5 Mountains was a resort powder day due to nasty avy conditions. In 18" of powder these boots were instantly impressive. I could drive my skis as hard as I wanted with no downside. Through chopped sections everything was handled with ease. I even managed to go off quite a few jumps and drops without problem. I did not notice a single downhill compromise with these boots compared to my Zzeus'. Fully buckled with the tongue and power strap, these felt like alpine boots. I normally ski with my boots fairly loose and even still, these boots performed flawlessly! On groomed stuff I was able to ski powerfully and confidently. Again, no downfall at all.
Now onto touring. I did a day of laps at the local hill, and a longer 7hr, 5500' tour in the backcountry. It probably doesn't even need to be mentioned, but touring with these boots is absolutely amazing! They feel like hiking boots with the tops completely unlaced. The 60 degrees of rotation is for sure noticeable on the flats, allowing my stride to be far more natural and longer also. I skin without the removable tongues because I see no reason not to. Some people say they're too fiddly and such, but honestly, it takes maybe 10 seconds to put them in and even less to take them out. Fiddly to me is having to deal with 4 buckles at varying tightnesses and a powerstrap along with a walk/ski mode that often get bumped. That is fiddly. The TLT 5's are not.
The flexibility of these boots helps me to climb steeper slopes without needing to switch the heel riser. I can now climb slopes in the lowest setting when previously I would have needed to go to level 2, and so on. The less stiff nature of the boots also allows my feet and skis to sit completely flat on the ground. This is nice when skiing down hard pack or groomers, but most useful when skinning on off-camber slopes. My ankle can flex naturally, allowing my ski to sit flat against the slope while traversing. This of course is no substitute for digging in the edges, but it works well for shallow slopes that previously just aggravated muscles and tendons in my ankles and knees.
I did try skiing once without the removable tongues. This was done on a wind blown slope with pockets of powder. While not horrible by any means, and most definitely an easy solution to shorter descents, I prefer the extra stiffness the tongue provides.
What won the TLT 5's over my other options (Scarpa Maestrale, and Dynafit Zzero) was the touring mode, cuff rotation, extreme upgrade regarding weight, and the simplicity. For a while I was concerned that these boots would be TOO far to the extreme compared to my Zzeus', but after a few days of skiing, I was wrong to think that. I have a bit of a looser fit in my 27.0 size and haven't had a problem with cold feet yet. My feet did get "cool" while sitting on the lift, but never cold. By the end of the run, I was sweating and my feet were hot. I also like being able to finally use a slightly thicker sock.
Now for the necessary "bad" parts of the boots. Ummmm.......this is difficult to find anything...the top buckle that holds the black cable in place is kind of hard to open when wearing thick gloves. The removable tongues are kind of awkward to stash when not in use. I did 7hrs of touring with them attached to a carabiner on the hip belt of my pack and that seemed to work fine. If they could maybe just vanish when not in use, and re-appear when I need them that would be great, but so far the hip belt solution is working fine. They don't get in the way, and they go pretty much unnoticed. Yeah, that's about it. I know some people complain of losing the lower cable, and I did have one come out on a pair of boots in the store, but mine are holding strong so far.
Overall these boots are what I should have been skiing. They ski downhill in a myriad of conditions without problem and without any noticeable downfall in my opinion. Perhaps if I were 6'5" 230lbs and skiing 190 Megawatt these boots may be bad, but honestly, if you're in that situation, realize you need to be reasonable with your equipment choices. Being the size that I am, I can enjoy the lightweight equipment safely. The Performance model may be stiffer, I'm not sure as I've never even seen a pair in person. These boots tour amazingly and the cuff rotation is perfect. I added miles to my tour without a second though and my legs were really fresh after 5500' climbed.
If you can, test these boots out. If not, make sure you are being reasonable with your gear choices and go for these boots, you won't regret it!!