Wow, that is a good price on charge controllers. I might give one a go if I add solar on the shop. I just did a quick look at them. 120a is pretty overkill, since I'll only add about 3kw though. I guess we will see.
When it comes right down to it, I usually shell out a bit extra and get a good name charge controller. I wrecked quite a few batteries with cheap ones and decided that it was a bad place to save money.
How does that charge algorithm seem on these Growatt?
I've never dealt with Victron. They have always seemed a bit overpriced to me, but most reviews are fairly positive.