This is not properly a "Mountaineering!" post !

But here's my blow-hard two cents !

A floorless tent is far less prone to condensation than a "cheap-o single wall tent ! "

Also, the very nice thing about condensation (also leaks, spills, etc) in a floorless tent is, it doesn't collect on the floor, because there is no floor. This is a huge advantage in many circumstances. The most extreme example might be emptying pee bottles in deep snow and deep freeze.

No problem!

Another nice thing about them? There is distinct tendency for them to be much larger than tents with floors. Cramped tents and condensation don't mix well.

Adding to a random list of advantages, the floor of a floorless tent is guaranteed to never wear out or require maintenance of any kind.

The only particular concern is to select a site such that in the event of heavy rain, you don't find yourself where surface water collects or runs off. When using a tent with a floor, this is also an important consideration, although slightly less critical.

Although they are in the main as stable in wind as any other tent, there can be some difficulty protecting occupants from wind-chill via infiltration around lower edges.

This problem varies with set-up, and the particular design of the tent in question. Assuming a door of some sort, the concern disappears in snow, when the stuff is banked around the edges very effectively. Especially in the autumn in deciduous forest, fallen leaves can serve a similar purpose. In very unfavorable circumstances, I've used stones and logs, but this cannot be recommended.

My personal dogma, is that a sleeping bag cover or bivy of 1 pound or less, is ideal addition to camping kit, provided that it is highly breathable.

This works particularly well with tarp tents as the cover seals you from the wind, and enables one, if so inclined, to dispense entirely with ground sheet, wlthough this becomes dubious in mud.

Assuming careful selection of equipment, the added weight of sleeping bag cover can simply be deducted from weight of sleeping bag, and for equal weight one ends up with an equally warm sleeping system that is more durable, versatile, and weather proof.

My girlfriend strenuously (but so far ineffectually) objects to lack of floor in a hot and humid forest in New England summertime, due to forest floor insect life. Since these creatures don't bite for the most part, it's a matter of personal tolerance during 10 weeks of the year.

In coastal Northwest mountains, California deserts, and certain other environments, ground-dwelling insects are far less in evidence than in Northeast, though admittedly, there are large slugs in Western Washington's lower elevations. Certain beach environments may have biting flies that live in the sand. Sand, by the way, is absolute hell on tent floors.

Mosquitos are another matter. Keeping doors closed works well with floorless tents. But full netting & floor is probably most effective in severe conditions.

I own four floorless tents currently. My favorite is the Hex 3, now with a new name and same design. It's a great shelter for one or two people in four seasons. Extraordinarily resistant to wind due in part to its hexagonal shape. Very easy, or relatively easy, to stake down tight to the ground, unlike some others in class. Similar design used by Scott in Antarctica. Failure of expedition was not due to tent design.

Second favorite is Twin Peaks. Bigger than BD Betamid, or not bigger ? It's now "new and improved, sold as "Twin Sister" with addition of storm flaps intended to address wind and bug infiltration. Two rigid poles and eight or more staking points = extreme wind resistance relative to most tents. Its lower profile and volume makes it warmer than Hex in winter.

Henry Shirer tents I don't own, but I have something very similar that was briefly manufactured by Mt. Hardwear, called Batwing. I can tell you that having an open front makes little sense in hard rain. The mosquito netting is nice enough in front, but I have some doubts about the fringe along the edges.

My fourth is SilShelter -- supposedly a 2-person. After a couple of weeks of increasingly cold evenings, I found it too small for one person. With a zillion staking points designed into the thing, it can be made secure in a wind. The door design is freaky, and not particularly worthwhile.