The Zpacks Duplex is awesome. My wife and I have ridden out several heavy Sierra downpours and a few steady hard rains that went on overnight with no problemos. The dual doors and perimeter netting provides good ventilation, never any significant condensation yet, even beach camping in January. It's only been a couple years, but no signs of wear yet. We've also been fine in Silnylon TartpTents, but Cuben fiber is the bomb.
We've use a couple different TarpTents for many years with entry from one end and condensation is sometimes an issue. It does run down the sides, but silnylon tends to "mist" inside and stretch when saturated. I hear the same from friends with similar shelters in CF and silnylon.
I considered the HMG shelter but it was a little heavier and more expensive. If you like modular tarp and bug net, or if you're hard on gear, then HMG looks like a good way to go. All the HMG gear seems more durable overall, but more costly and a little heavier.
I also considered the Six Moon Designs Skyscape X CF model but it oddly didn't have 2 doors at the time, and it was always out of stock. Their new model now has a zipper on both sides, but its only a solo version.
TarpTent Cloudburst on Left; Zpacks Duplex on Right
Packing up after a booming "afternoon thunderstorm" that went on all night.