My thoughts on these:
- The price on the Siemens Versicharge is appealing, but you'd need to use Tesla's J1772 adapter to use it with a Tesla. If, for convenience, you wanted to keep a J1772 adapter semi-permanently attached to the EVSE and keep another adapter semi-permanently in the car, then the price would go up to within a few dollars of the price of a Tesla Wall Connector, and the latter will charge at a higher rate (given appropriate wiring and breaker). Thus, I don't see much advantage to this for a Tesla-only garage; however, if you have a non-Tesla EV in addition to a Tesla, this looks appealing. There is one big caveat, though: According to this thread, some Siemens Versicharge units don't work well with Teslas. Thus, before buying one of these, I'd research this issue more thoroughly and be sure the specific model number in question is not one of the affected units.
- The AxFAST unit looks less capable than a Tesla Mobile Connector, which sells for $275 ($35 more than the AxFAST unit; or $70 more if you bought a 240v adapter, since the AxFAST comes with a NEMA 10-30 in addition to a NEMA 5-15). Thus, if you lost your Mobile Connector, I'd favor buying another one rather than the AxFAST. The AxFAST looks more useful as a wall-mounted EVSE for a plug-in hybrid or as a take-along unit for a non-Tesla EV. I suppose if you owned such a car in addition to a Tesla and you had a weak enough electrical system in your home, sharing an AxFAST might be better than charging at 120v or sharing a Tesla Wall Connector via a JDapter or something similar, since those cost almost as much as the AxFAST.
- A JuiceBox 40 for $550 actually does have some appeal, since these units have WiFi connectivity, so you can gather usage data, control them remotely, etc. In some areas (mostly in California, I think), utilities offer programs to enable you to charge when there's an excess of "green" energy available if you use a JuiceBox, which might be a plus. Unfortunately, the remote control features don't work that well with Teslas, which won't wake from a sleep state when the EVSE signals it can deliver charge. I gather there's a workaround that involves charging at a low rate, rather than not charging at all, but that partially defeats the purpose. You can also collect charge data from a Tesla using its API, either manually or via an app or Web site like TeslaFi. Overall, then, this is a bit underwhelming, but there might still be use cases where it'd be appealing for a Tesla owner, particularly if the Tesla bug that prevents the car from waking when the EVSE's charge availability changes state is fixed.
In sum, I think most Tesla owners would be better off with Tesla's Wall Connector or Mobile Connector; but there are some cases, mostly involving multi-EV households with both Tesla and non-Tesla EVs, where a J1772 EVSE might make sense. There are big caveats, though; and in particular, the Siemens might not work at all, based on the thread I referenced earlier.
FWIW, I own a Clipper Creek HCS-40 with a JuiceNet board installed. I bought it for a Chevy Volt that I drove prior to getting my Model 3. I mention this to point out that I have experience with home charging a Tesla with a non-Tesla EVSE. It works fine for me. I have two J1772 adapters, one that "lives" on the EVSE's J1772 handle and the other that I keep with the car. The only advantage of a Tesla Wall Connector for me would be that the Wall Connector can open the charge port on the car by pressing the button on its handle. That said, I use what I've got because I bought it before I bought my Tesla. If I hadn't had the Clipper Creek EVSE when I bought my Tesla, a Tesla Wall Connector would have been a better purchase for me.
