And I'm trying to find a fun, moderately-optimized way to use them. Forge World hasn't really gotten its act together yet this edition, so their rules leave a bit to be desired compared to last edition, but I think I have an inkling of how I'd like to use them. I'm thinking of bringing an aeldari list that includes harlequin and drukhari elements to get access to as many leadership debuffing effects as possible. Team those up with Irrilyth and the spectres (including the exarch), and I ought to be able to start evaporating enemy units with morale checks starting around turn 2 (because many of those effects require I get closer than deepstriking will allow). I can also mix in a farseer and shadow seer to take advantage of the enemy's reduced leadership with mind war, mirage launchers, etc.
So yeah. 8th edition freakshow is the general idea. Does that seem like a reasonable foundation for moderately-optimized games?
Also, what are your thoughts regarding the exarch upgrades? The exarch-only weapons seem like a trap as the haywire blaster is heavy on a platform that will generally want to move quickly, and the prism blaster trades range and AP for damage that won't matter against most of the infantry units I'll likely be pointing the spectres at. Plus the prism blaster loses the heavy flamer profile.