As a new user, (just started SF in Jan or Feb), I’ll add my experience for Tungsten to consider and maybe it’ll help some. In terms of Full Frontal and your lower than expected results for FTP. I do find it odd that you blew up and quit, but the ftp is lower than anticipated or compared to other virtual apps.
For me, I did the 4 week intro training and then the Full Frontal prep plan and then the test. I got through FF fine, (I’m used to pushing myself from a bike club I’m in, and solo riding). My FTP result was about 25 watts lower than it was from an actual 1 hour outdoor FTP test I did several years ago, and about 8 watts higher than an FTP test I did on RGT virtual. I found that a bit odd that it was lower than my outdoor ftp, but I was trusting the science and I did have trouble using Level Mode during the test Vs the ERG mode that makes up the FF prep plan.
That being said, I stuck with that lower FTP and found that many of the post full frontal workouts in the All Purpose Road Training Plan that are based on the FF measurements, are actually spot on. I mean I am amazed at how close the targets are to my physical ability. Some of the workouts seem way too easy, but others will really wear me out, (like Omnium that I did tonight I literally went to failure twice).
I am trusting that it’s working for me and is helping condition me. With the nicer weather I have it setup to do indoor and outdoor workouts and I do some in between pleasure rides as well. I can absolutely tell that it is making a difference in a positive way. Honestly my only hang up with the outdoor training is that it’s ridiculously complex and quite frustrating. (if only there was an app for that developers).
Like you, I really enjoy the other aspects of what SF offers, like the Yoga, Mental and Strength training. I do them all. I have considered quitting Sufferfest many times because I’m on a training plan that includes outdoors, but there’s no easy way to do the outdoor workouts. It’s absolutely infuriating… But I press on, because it’s way better than just riding without a plan, and for me Zwift was too gamey and lacked a smooth smart trainer integration. I liked Rouvy, and RGT, but riding without a plan is what I did for years with marginal gains, so I am counting on the science to get me to the next level.
Hang in there!