Well, that's certainly another opinion. I personally like to understand the technology around me so I've gotten enjoyment out of building and understanding how my EVSE (the charger is in the car) works. I went so far as to learn about the protocol the car and the EVSE use to negotiate the charge rate and other commands.
I recognize this isn't for everyone. Some folks are going to pay an electrician to install Brand X EVSE and that's perfectly fine as it gets more EVs on the road. Others, like me, don't pay people to do stuff like that. I repair all my appliances, do most of my own home improvements, and enjoy tinkering. This is all motivated by my desire to learn how things work.
My assumption, perhaps incorrect, is that if the OP is looking at OpenEVSE units, there must be at least a little interest in the DIY element. My goal would be to encourage that as the kit is "fun" to build. But I also miss HeathKit and RadioShack (the old one) so thats an indicator of my perspective.
Again, either way, you'll find that the elements that make up the EVSE that Chris offers are of very high quality. They are more expensive than sourcing them elsewhere, but not to a huge degree. You will certainly come out with a higher quality EVSE by buying or building an OpenEVSE than you will going with something like a Blink or ChargePoint home EVSE. The only other EVSE I've seen that looks to match OpenEVSE quality is Clipper Creek. GlennD is highly knowledgable about the inner workings of EVSEs and electronics and has a comfort level sourcing parts that allows him to build them at a much lower cost. I'm not at that level, but he has even shared parts with me in the past for other projects. I still need to build that LEAF DD!
Anyway, whatever the OP chooses, good luck and come back here if you have any more questions.
BTW: The Blink EVSE was UL Listed for all the good that did.
[s]2015 LEAF SV in Gunmetal Gray[/s] Returned 2/2018
"The only gas in this vehicle comes from the driver."
I drive a LEAF, it doesn't have Ludicrous or Insane mode. It only has Slightly Annoyed mode.