These are like speed-bleeders for brake calipers: a slight convenience that comes with the slight risk of tragic consequence. I could see using one if the drain plug were difficult to access, but changing the oil on our cars is super easy. Guys with long arms have even done it without raising the car.
Things to consider:
1) drain speed - draining oil actually takes longer through a valve, since the hole diameter is smaller.
2) incomplete drain - the threaded portion of the valve may extend up into the pan (Subi owners have confirmed up to 3/8" overshoot). This means not all the oil comes out - unless you remove the valve. The amount of oil, according to one report is "about 10 seconds worth".
3) protrusion - the valve hangs below the pan significantly more than the OEM screw head. If you've ever scraped a pan, you know what can happen here.
4) leaking - valves can leak. Also, they can be opened unexpectedly. Probably won't, but can happen.
5) service - if you ever have your oil changed by a lube shop, the valve complicates things. But every idiot knows how a drain plug works.
6) the risk - complete engine failure without warning if the valve fails, opens, or is damaged.
It's a neat concept, and I don't doubt these valves are mostly reliable for this application. But imo, some things are better kept simple/stupid.
_________________'98 SC Riviera • 281k miles • 298 HP/370 TQ • 0-60: 5.79s • ET: 13.97 @ 99.28 • 4087 lb • 20.1 avg MPG • Nelson Ledges Lap: 1:30
3.4" pulley • AL104 plugs • 180º t-stat • FWI w/K&N • 1.9:1 rockers • OR pushrods • LS6 valve springs • SLP headers • ZZP fuel rails
KYB GR2 struts • MaxAir shocks • Addco sway bars • UMI bushings • GM STB • Enkei 18" EV5s w/ Dunlop DZ101s • F-body calipers
EBC bluestuff/Hawk HP plus • SS lines • Brembo slotted discs • DHP tuned • Aeroforce • Hidden Hitch
^^^ SOLD ^^^ '05 GTO • 85k miles • 0-60: 4.8s • 16.9 avg MPG • Nelson Ledges Lap: 1:26
Because fun'70 Olds Ninety-Eight Holiday Coupe • 116k miles • 455 Rocket V8
Because cool'95 Celica • 152k miles • 0-60: yes