Re: Comparison with HPQ and/or Lenovo equivalents?
"Is iDRAC (etc) based around Intel AMT/vPro which seems to be increasingly out of favour with what used to be called the "tin foil hat crowd"?"
No, it's a type of IPMI - and almost unusable without buying the (pricey) upgrade license for full functionality.
As others have mentioned: Supermicro build the IPMI in (they used to be optional, but stopped happenning 7-8 years ago). There's an optional upgrade in a lot of newer systems to allow bios flashing via the IPMI but that's not 100% necessary and doesn't affect standard functionality.
One other factor not mentioned when buying servers: ALWAYS factor in the cost of 3 or 5 year support when comparing prices, not just that of the hardware.
You're stupid not to take this unless you've got a LOT of hardware and can afford to carry spares yourself (take 8*5*NDB. The higher levels of service are only useful for critical kit). It's cheaper to buy this upfront no matter what brand you get and it means that if there's a problem you get parts without having to jump through a mass of hoops to get them.
If you have a serious server room, then you need one of THESE: http://serverlift.com/solutions/products/sl500x-server-lift/ They're cheaper than paying the medical costs when someone gets injured lifting heavy kit into a rack (and they make installation of just about anything a relaxed one man operation, no matter how large/heavy.)