I checked out the Mountain Hardware Skyledge Tent vs. the Hubba Hubba HP and what I found was that the Hubba Hubba HP is wider (50"vs 46" and 40" in the back of the tent), but a little shorter (84"vs 88"). Therefore you will feel more cramped in the MH tent that the MSR from what I can see (unless you're tall). The other issues I see with it is the 3,000mm coated floor (not very waterproof) and the full mesh canopy. It's also heavier (4.28lbs vs. 3.69lbs). You mentioned you might like to use it in the winter and I think any full mesh tent (including the Hubba Hubba) is a bad winter choice.

I think you should give a serious look to the Hubba Hubba HP. Cascade Designs designed this tent specifically for limited 4 season use, but one that also excels in the hot, humid days of summer. It is lighter than the standard Hubba Hubba (less than 4lbs), will be warmer and more versatile than a full mesh canopy tent in the winter, and the material breaths exceptionally well for summer use. It has a super-waterproof floor (10,000mm coating), all the guy-out points are reinforced with welded patches in case there is significant wind, and you won't get the cold drafts blowing in through like you would with mesh. It can be pitched very taught when the fly is on which is important for really bad weather (that taughter the pitch, the better it can withstand wind), and when the fly is on, it has excellent ventilation.

My own personal experience had me near the summit of Cotopaxi (19,200 ft volcano in Equador) using the Hubba HP. We experienced 30-50 mph winds and the temps got down to about 0 degrees F. The tent did exceptionally well, withstanding all of the wind bursts and blowing dirt. I didn't need to guy it out, but if the wind was stronger, say 60+mph, I would have been able to take advantage of the reinforced fly, something that would have made me nervous if the fly wasn't reinforced. I was amazed this tent did what it did at around 2 1/2 lbs! I had plenty of room to change into my mountaineering clothes, sit up in my camp chair while weathering a storm, and stayed completely dry. One of the best features, but often overlooked, is it's entry way (both on the Hubba HP and Hubba Hubba HP). Because the tent's ceiling extends well over both doors, you won't have rain and snow dripping inside, even though it is a side-entry door. This is something I would have you pay attention to as you're looking at tents...

The only 4-season issue is snow-load capability which most very lightweight tents suffer from. The other disadvantage is the price at $450. However, because this tent does so much (roomy, light, two door/vestibules, etc), it might be what your looking for.

Just some thoughts...