I have been riding for over 20 years and thought to give TR a go and I have given sufferfest a go as well as zwift bkool etc but what I have found with TR is I do an ftp test which actually comes close to all my other test including out on the road but when I am asked to do a workout they are way too hard and I have to reduce or give up. With sufferfest I am set at the same ftp which using their 4DP comes out at pretty much the same as TR but the workouts stretch me to the limits but I can finish the rides feeling I have achieved instead of failed. There must be something in this 4DP. I am not a die hard user of any system. I simply have to go with what works for me and right now it looks like sufferfest provides entertainment, yoga, strength and of course training plans for way cheaper than TR. so when my subscription ends that will be it for me on TR