I have tried quarry tiles, the hearth kit, and the fibrament.
Quarry tiles didn't last long at all. They would break a lot and always shuffling around so I got sick of them. They are cheap though.
The hearth kit is a big heavy mass that I have a hard time heating up unless it's in there a long time. I usually only use it to make bread and take it out when I'm doing pizza. If I try to use it with the clean cycle it doesn't get as hot as the fibrament for some reason (probably because my oven heats from the bottom and it is a lot thicker with sides). I can get it to around 700-750 after a 90 min heating where the fibrament gets to 850 in the same time. On the other hand, the thing retains heat for a long time and I can easily bake off loaf of bread in it while my oven cools down from pizza.
The fibrament is great though. I have the smaller one (15.5" i think) but that works great for what I use it for. It is a brute and takes a lot of abuse (I routinely have it up above 800 degrees). It is also a manageable size, unlike the hearth kit, which literally bows my oven racks because it is so heavy and it's a pain in the ass to move around or take out.