I have had the Voltec L2 for almost two years and a LCS-25 for 18 months. Neither has ever failed. The Voltec was professionally installed and has a 3 year warranty. I find the coiled J cord to be very heavy. I only stretch it about 8 feet but the strain reliefs at either end are already cracked. Any more stretch and you are significantly increasing the side load on the ends of the cable and on the charge receptacle on the car. It does have a light on the J plug.
The Clipper Creek is showing some distortion where the cables enter the relay module but I can not predict when they will fail. Could be years.
Since the LCS-20 can be bought for much less I would get it.
2013 Volt base Blue Topaz Metallic, leased February 2013, 30000 miles at turn-in. Zero problems!
2015 Volt base Black, since November 2014, 38000 miles
2017 Volt LT Kinetic Blue Metallic since March 2016.