We have one and use it constantly. The lack of a top vent wouldn't faze us, as the temps for most all grilling can be controlled with the bottom vent. These things get hot...they get hot fast. We keep a ten-inch dia. plate in the kitchen to gauge what will fit on the grill, as the actual diameter of the newer grates is ten inches (the original ones were 9.500").
We even grill kabobs on it by using it as something akin to an Armenian tonir: the cooking grate AND the top vent are removed, and the kabobed skewers are inserted straight down through the top hole. It's kinda cool and they grill fast, too.
A couple of "normal-sized" steaks will fit at one time but one might have to be inverted, or indexed end-for-end, in the beginning, if they happen to be a bit larger. They can grill so fast, and at such high heat, that even if they were grilled separately it wouldn't be much of a deal.
Also, the darn things only require about three Dixie cups worth of lump to peg 650°F-750°F, and for much longer than we ever cook. The Mini can be ready to cook before our Large BGE is even thinking about warming up.
What it isn't all that groovy for, is using as a smoker. While it can be done, with some inventiveness required, to do so seems to us to be more of a novelty. Smoking a ham on one is similar to putting a model ship in a bottle: hopefully no real need, but it does confer bragging rights.
That the fire ring is broken is of almost no importance unless it is so smashed up as to be unusable, which would be fairly rare in our experience with BGEs. If the pieces of the ring will still fit together, then the ring will still function as intended, In fact, we manufactured a steel ring for ours that will allow a pie-plate to be used as an indirect barrier piece below the cooking-grid, for those times when we've lost our minds and just want to use the Mini as a smoker.
They will allow one to grill a handful of wieners or a couple-or-three burgers in no time. And.......it's really, truly portable, for those times you might want to run down to the park and become the envy of all the other picnickers while you prepare a feast.