I've had my XL sauna for about a month and use it nearly every day. Definitely what I was looking for.
Positives
* Heats up very fast - it gets to ~200 degrees from ~60 in about 20 minutes.
* Great aesthetic
* Nice interior cedar smell
Negatives
* There is a huge temp spread between the top bench and the bottom one. If you want to get hot you have to sit on the top bench.
* The top bench isn't very wide so anyone with any sort of shoulders (basically all men and most women) will not be able to lie down comfortably without crossing their arms. If your arms aren't crossed, an arm will dangle and your shoulder will be uncomfortable. This could be fixed with a wider top bench or a bench that pulls away from the wall 4-6 inches or so. I have laid a wooden backrest on that bench to give me some bench width for my shoulders but it isn't ideal.
I'm not sure how sturdy this unit will be over time but I like being able to lean back on the top bench, which doesn't look possible in cylinder sauna shapes .