Crysmalon said:
2nd edition - I ran the Eye Tyrant adventure series. So for a few months I presented roughly 25 beholder-types as enemies. Crazy. They're pretty complicated, not to mention deadly so I don't think I've actually had one in combat (used a couple as insane PCs providing info) for years.
Ha! Ha ha ha!
Complicated? You want complicated, try running a Gibbering Orb (from the ELH and Epic SRD)! If 10 eye-rays are too much, try
two dozen- containing not only most of the Beholder powers, but also such fun things as all three Power Words, Prismatic Spray and Cone of Cold in ray form,
Disjunction in ray form for that matter... I could go on. Those beasts are truly, off-the-rocker nuts.
And yes, I've used them- one combat I ran in my Epic game a few months ago featured, not just one measly Gibbering Orb, but
four of the things- templated with Elemental templates no less- along with the Uvuudaum Sorcerer that made/called them. That, combined with (on the PC side) a 28th-level Wizard NPC, and seven actual PCs made for a fight that took us two and a half whole sessions to fully resolve (though admittedly the Orbs were all dead at the end of the first session).
Answering the OP's question more directly, I've also used regular old vanilla Beholders in game a couple of times, and even one templated one. Oddly enough, the first time I used one most of the players had no idea what it was, even one of the powergamers of the group. I was actually a little disappointed; I'd been hoping for more terror on the part of the players when it showed up. I've also used Gauths (the little 6-eyed lesser beholderkin) a few times, back when my games were lower-level.