I get nervous when I read "The canopy is built with highly water-resistant and breathable [fabric]." Have you used it in serious, sustained rain? Had it for long enough that the DWR finish wears off? And what are its advantages over any other single-wall tent?

Not criticizing; merely asking for more information. It's not a tent I'm familiar with.

Thanks.

mark

So I bought the black diamond hilight tent, because of size and weight. As i had to cancel my trip to magadan, I only used it once this summer. TO be honnest, I am disapointed. This tent is quite expensive +400 euro, and looks very cheap to me... First I find it not normal that you have to seal it on your own for this price, they even say that you might need more sealant than what they give with the tent....
Then It's super light but looks super fragile to me.. We will see. I sent one night under heavy rain, and inside was wet because of condensation. I didn't buy the optional hall, so when I open the door from the tent, the water comes inside...

Am I asking too much for 400 euro or what?

I have been using the Big Agnes Copper Spur UL2 this season and I so far so good. Two vestibules for stuff (but of course no floor so things will get wet from water running in), good venting and most important is that I stayed perfectly dry after a night of heavy rain - and on more than one occasion; inside mesh pockets for stuff; packs very small and good weight. Only suggestion, buy a three man for one person and a 4 person for two people.

Here is what it looks like in action.

Superlight means thin fabric. You can't fight physical science. That doesn't mean fragile, exactly--maybe, maybe not. Since it's sil-nylon and Black Diamond, I'm guessing it's quite strong, and probably has good UV resistance too. But that's the sort of thing you should have looked into before buying, right?

So what you did, was you went out and bought a cutting edge, single wall tent because it's lightweight. What you got was cutting edge design and materials, which alone are responsible for half the price you paid. Shaving that last kilo off the weight is expensive, you know. You got an outstanding return and warranty department , in my experience. And you probably got good workmanship, although judging by your complaints you're probably not ready to appreciate that part.

You also got....Condensation! That's what you get in a single wall tent! If you don't want condensation, you buy a double-wall tent (heavier), or a bigger tent (heavier), or a better ventilated tent...or all three. See how this works? There are tradeoffs every step of the way.

I share your feelings about the seam sealing, but a lot of manufacturers do that. It's irritating, but it's commonly done.

What you still don't know is whether the tent will remain waterproof. That appeared to me to be a dry land tent--suited for deserts, maybe high mountains, as well as for people who want lighter weight gear even if it means they might get a bit damp from time to time. If you're not one of them (as it appears), you might prefer a very different tent.

Not trying to criticize--just trying to give you some belated sense of the stuff you need to consider before dropping coin on an expensive tent. When I looked for something similar, I ended up with a Hilleberg Akto. It looks like the Coleman Libra X3 pictured in a post above (the Coleman is a shameless copy featuring inferior materials and workmanship but a lower price). It's sil-nylon, 1.5 kilos, four season, and well-built. It's also double-wall, so minimal condensation considering its air volume is tiny and it's designed to shed extreme weather. No way I'm spending bad weather in a small, single-wall tent. But the Akto is smaller.....and more expensive. Like I said, there are always tradeoffs.

Mileage varies.

Mark

I have a Big Agnes Copper Spur tent. ultra light (3 pounds) expensive ($400), but designed and built well. I slept in it over 100 nights last year and about 30 thus far this year. I like the two doors and vestibules on both sides. I usually cook under one of the vestibules unless I am in bear country. They are out of Steamboat Springs, Co. REI carrys them too.

Ultralight doesn't mean ultra weak
 

If you are looking for a genuine ultralight tent that is 100% waterproof and windproof - made from Cuben Fibre (a sail making material); check out
ZPacks Hexamid™ Long Tent or Tarp ZPacks.com Ultralight Backpacking Gear - Hexamid Long Cuben Fiber Tent

At 600grams (21 oz) it packs to the size of a camp pillow, can be carried easily and barely noticeable whether you are doing a lot of camping or just a little.