I've sat on the Tullsta, and found it pretty uncomfortable. I'm tall and found the depth of seat insufficient so get I was perching and unable to relax. I'd consider it a chair for the bedroom that you sit on to put your shoes on or as a clothes horse rather than a proper chair to sit and read in.
The other looks more comfortable to me based on my comments above.
We have two of the jennylund chairs. They are ok but need 'wearing in'.
When they are in the showroom, lots of people have sat on them. When brand new they are a bit 'stiff'.
We are pleased with them.
The problem has been solved. While out earlier I took a look in several antique/second hand shops. One had a tub chair similar in size to the tullsta...but solid with a wood frame,sage green velvet upholstery,and the *most* comfortable squishy seat...down most likely. All for £45 inc delivery. Yep...I bought it.