Congrats on your new car and welcome to the forum.
We have members who have Voltecs and AFAIK we haven't heard of any real issues (I have a Blink so no firsthand experience). However, at some point quality does follow price and other more expensive options probably do have a better build quality, though that hasn't been apparent so far.
Your electrician is definitely off-base as far as the power consumption when charging on 120v versus 240v. Charging on 120v might be 10% less efficient in the worst case. Probably more like 5%. The difference is simply that there is a constant amount of overhead used per minute of charging, and it takes longer to charge at 120v. Or put another way, you're losing a constant amount of energy and C/120 will be a larger number than C/240. Over the course of a year the cost of the inefficiency would probably be less than $50 and likely less than $25. (Assuming 10K EV miles, 32 kWh used per 100 miles, 10% efficiency loss, and < $.15/kWh). However, if you do a lot of short trips, like on the weekend, being able to charge faster will allow you to have more EV mile and fewer gas miles.
If you're on a tight budget you should be able to use the 120V charger without any real issues. If you want to try a 240V charger I'd go for the Voltec at the low end and the Xpress or the EVSEupgrade at the high end. If you go with the 120V, try and get a separate circuit put in. That will avoid many charging issues.