Got the spectre good 2 or 3 man depending on whether you get the 200 or 300 version. I really like it. I use it as my heavy car camping tent.
Banshee is about 500g lighter probably because it is a lot smaller. Condensation is worse I believe still if up to 6' tall its ok indeed good for a two man (if close with other person).
JW Gossamer - correct me if I'm wrong but that is a solo tent weighing about 1.3 or 1.5kg, has no porch, inner is totally mesh and inner is permanently attached to the fly at the point the single hooped pole goes through the sleeve. It has a very low headroom too. Itis called a tent but a lot of peopl who have used one (myself included) would call it a hooped bivvy. You won't sit in it and you have no space for gear unless you can fit your boots in the less than 3/4" space near the head of the tent where the difficult to get into entrance is. You can get your boots there but please bear in mind your head is probably going to be too close to where your feet had spent most of the day, there could be an issue with odour!
Seriously though, it is drafty (all mesh inner), it is tiny (in height but the length is very long 2.4m inner) and your gear needs to stay outside. In good weather though you can roll up the flysheet a the short head end to the pole sleeve and the longer foot end too. Leaving the head end free to the stars (with bug mesh of course) or the feet (good for smelly feet I suppose) or both (why?). It does however have a tough durable base groundsheet comparable to the MAcpac minaret (10,000mm HH) and it is £80. Like I say I used it when my new tent was going back to the manufacturer for a replacement check and was loaned to me for a trip by the shop as it was taking too long to get the faulty new tent checked over (not this one). I wouldn't spend £80 on one, not worth it because it doesn't fit into any use bracket IMHO. Still the shop I bought mine from sold quite a few but I have only ever seen one in the countryside excluding the borrowed one (in a campsite in the Lakes).
Out of those I would say the spectre is the best in size features and as a two man 2.5kg split in weight it is not too bad really. It can easily fit two 6'5" tall people I am that tall and once put two full sized mats in and lay on each and reckon I had enough room fo two of mea and then some.
The Banshee is good for smaller people. It is a two man but upt ot 6' and condensation is more of a potential problem than the spectre. It islighter and at 2.0kg it is possibly ok for solo use as well as two smaller people who don't mind contact in the night.
JW Gossamer - No thanks! Forget it unless you want a heavy hooped bivvy. If you think of a ridgeraider at bargain prices and a lot heavier. It is two skin but one is a mesh skin that contacts the outer near the long span from the pole to the foot end. It even has a sponge pad there to try to keep it away. I could not get changed in it without straining rather hard and doing a maneouvre akin to holding a partial stomach curl or situp while putting my pants on!!!
I hope that helps!!