I cannot comment on Racktime.
I first dealt with the Topeak "track rack" some years ago with our trikes. I still have one of the bags from that time and it's as sturdy as ever if a bit more purple than black now. I have never had a rack break on me outside of normal usage issues that would be common to any rack, and even then was only related to a lower screw that was easily replaced. The racks themselves have never failed me. I use one on each of my and wife "cruiser" bikes. One is the GIANT trunk bag that she puts all manner of goodies in. Mine is a bit smaller with some (mostly worthless) little panniers that fold out of pockets on the side. I have not found anything wrong enough with them to consider going to a different system. With that said, I also utilize an under seat bag they have that clips on and off. It works in wonderful concert with the smaller of the two rack bags, given my seat height.
The smaller of the bags would likely be good as a small front rack bag, but probably not worthwhile taking up a whole rack for touring with unless CC. The larger bag is of a useful size for an overnight bag, a day of food, that manner of thing.