My take is that infest effects are either really good or they don't do shit. So swingy in that way is how I would describe them. And this goes for burn as well IMO. And that's why I sort of like the scaling ones because they are never useless even if they are not cost effective. I value flexible removal over cost effective removal personally.
FWIW, I really like BSZ. Permanent -1/-1 counters is a unique effect that screws over persist (a mechanic that could use hate). It also shuffles your library. And you can redraw it later, so it's like having more than one removal spell in your deck while only costing you a single deck slot. It's a very good control card. I even really like it in aggro/control shells as an "oh shit option". Sometimes you need a reset button when bad things happen and this works great for that, being able to sweep tokens easily or even a field of fat if you have the mana. Again, the flexibility is highly valued here.
BSZ also has a really sweet full art promo, so if you like pimp and dig full art in particular, this card really deserves consideration.