Just my opinion....
I happen to have both, and frequently use both for various reasons. I have a Miele 1966, and '79 G.E. Filter Flo.
For instance, I rarely wash whites in my Filter Flo. Why? Cause my Miele can do the same thing in one 120 degree wash, that my Filter Flo would take doing a 130 degree hot wash with detergent, then another warm wash with bleach, and 2 rinses. So, lets see....13 gallons of cold water, heated to temp OR about 100 gallons of water, almost half of that water from the water heater.....
In regards of cleaning, there is no comparison if you ask me. Even an unheated wash in the FL will make better results in the end. One, cause of the way it washes, two, cause of better rinsing. I rarely pre-treat stains in the Miele. Typically, I will wash colors or bedspreads, or the occasional load of towels in the Filter Flo. If I need something in a hurry, its the TL...thank God for mini-washes. Everything else goes in the Miele. Basically, some clothing need more water to get cleaned and rinsed properly. So, in that case, I use the TL. If cleaning or "sanitizing" is needed, I head for the FL. Do not get me wrong, my Filter Flo can clean like a son of a bitch. It really does do a great job. Yes, even with stains and whites, I do not worry much. It just takes a little more user attention to get the same results; not to mention water, detergent, and electricity.
I like OLDER TL washer. Not this new age DD crapola in plastic, that beats the dirt out. I used just the Filter Flo as my daily driver for quite a while, and then when I got the Miele, realized how much easier it is to get better results. Then again, I still prefer a TL wash for somethings, and for the entertainment factor. So, I would not wanna choose one or the other. Each has their own advantages and disadvantages. BUT, if you are just looking at over all cleaning results, it is my opinion that a FL is always the way to go.