First a note about prices:
1. As mentioned before, the prices online are always more expensive than if you buy in the store, though a coworker of mine mentioned there are sometimes decent sales online that partially offset this.
2. The store near me has had a black friday sale (day after thanksgiving) for the last couple years that was very good. For the first hour they were open everything was 30% off. It requires getting up really early, but the savings can add up to a huge dollar amount if you are planning to buy a lot of pieces.
I don't know if all the stores do this, or just some, but it might be something to check on if you want to save some cash and don't mind waiting. They warn in advance that they don't have the sactionals in-stock for the sale - I didn't actually receive mine until January.
3. I think there is some price reduction and other financing options if you finance through them (a lovesac card). I bought during the sale mentioned above, so they said none of this was available.
Durability-wise, a friend of mine has had them for several years (and through one move) and they still seem to be in great shape.
I think they are really comfortable; soft but also supportive. The covers play a big role in the softness IMO. Going between the "rhinoplush" covers and the khaki ones (which you can do in the store by jumping between floor models) is the difference between extremely comfortable and just ok.
My one really big complaint is that there is no way with to make a long and deep couch with the current components. The deep loveseat is great, but there is no way to make a deep couch go more than 2 sections (while still having the backs line up correctly).
I eyed them for a couple years before I actually needed them (bought a house), and this was something I brought up the very first time I saw them. The salesperson at the time said they were working on another piece that would allow you to do that, but it has been at least a couple years since then and there is no such piece available. All it would take would be a "short side", one the same width as the short side of the base.
I'm still hoping they will eventually make such a thing so I can add it to my existing setup. As of now I have as many deep sections as possible and have ottomans positioned within range of the shallow sections to assist with the lounging and slouching.
The size of the deep-wise section is perfect IMO. I can slouch and the edge still almost comes to my knees. Add an ottoman and it is practically a bed