I haven't used them but they look okay. There's a version that comes with SimonK firmware so you definitely want to consider it:
I actually got them at Quantum hobby - Tim's great - and local for me
The Spyder 30 amp Opto is flashed with SK as wlll- very cool!
Part of a new build with MT 2216 T motor V2
Did he give you a reason why a separate BEC is the way to go? Just curious as to why it's considered the "hot setup".
Several flight controllers take 5V inputs from the BEC of the ESC. The KK2 gets it off the throttle channel and I believe the MultiWii does too. The BECs from the other ESCs are unnecessary, but I've never run into problem having them. I know guys that swear by having only one BEC connected. BTW, you can power APM 2.5 with the BEC as I've done it before. I've read that it's not the preferred way to do it vs using the dedicated power input, but it works. It's a continuous learning process so don't hesitate to ask questions. We're all learning as we go :)