I can offer you advice as someone in exactly your position. I’ve just come off 2 1/2 years of virtually no excercise, I dusted off my bike when the sun came out, did a couple of rides and felt very out of shape. So, I got a Kickr Snap and got to work with Sweet Spot Base Mid Volume.
Sweet Spot intervals are hard But, they do you good. I’m 3 weeks in, and each session (except for the mid week recovery ones) has stretched me. But, I’ve made every one so far and now I’ve got half way through part 1 the motivation not to quit is gathering serious momentum.
I’ve already lost about 2Kg (no dieting, but I am more careful with wine and beer these days), I have no real idea of FTP gains yet, and I’m in no rush to do another ramp test, but the fact that I’m hitting every interval as they get harder is somewhat heartening.
If you did a low or mid volume Traditional Base you’d find it easier but you would also find it slower to make fitness gains. To be honest I’d get bored doing long easy intervals indoors and I’d get frustrated with slower progress. I’d rather do hard work in the time available and see bigger gains. If you have time to do 10 hours or more then Traditional could work, but 10 hours a week on a turbo isn’t something I could cope with.
My advice, go for Sweetspot first, put other ideas out of your head. Aim to get 3 weeks in before re-assessing. By then you’re half way and you couldn’t quit then, could you?