I did the same thing... I bought a singer 15-91 instead of a $1000 new machine to quilt on. Be prepared... once the 1st one moves in others tend to follow.
I now sew almost exclusively on the Singer, and have acquired a few other vintage machines... one of which is a Kenmore - it's not a bad machine - and my daughter sews a much straighter seam on it than the Singer - but for some reason I had never even considered trying FMQ on it.
I did finish up a king size quilt on my Singer last week so there is plenty of room - and if the 201 is bigger :thumbup:
ETA-- I think I just remembered the objection to 201 vs 15-91 -- isn't the 201 belt driven rather than solid gears? seems like I remember there being concerns about over heating and not being as strong to handle the bulk... but I think it's all theory since these machines have been around for 100+ years some of them and are still chugging along and have sewed far more difficult things than a quilt sandwich