I've seen the same, Sparks are great at non time-sensitive tasks. if you can set up a agentic loop that does not require human intervention, you can design around the memory bandwidth limitations
I’m getting 40tk/s decode with 1000+tk/prefill with a 198B-A11B model on mine
With the currently-in-PR implementation it doubles decode performance for all the tasks I've been testing it against, at in the worst case is still a 35% uplift, so on a box with heaps of compute and not much memory bandwidth, it's worth it in practice