I personally don't have any experience with ProMaxx, but its just going to come down to what you feel comfortable with and if the couple hundred dollars are worth it, like what was said above every brand will have their bad reviews so its hard to say. Everything ive read and seen say their better than procomp but that's not saying much, and with the thought of spray you might want to make sure you get something that will really hold up, better to spend once than to have to do it again.
This is my screwy way of thinking.
What makes them cheaper?
Let's try this.
Let's say company "A" uses premium materials, does all of its own R and D, limited marketing and advertising, build in America and only sold to select retailers wholesale with some room for profitability for the final point of sale to make a few bucks.
They offer a great warranty and stand behind the product.
They have model "ABC" for $1000, leaving a margin of about 18%
Now let's look at company "B".
They farm out all the casting to a lower bidder, copy products already on the market, source overseas labor, sell to virtually everybody, advertise like crazy, have a low margin making it a volume game to make any real profit and the warranty is only for defects and workmanship for 90 days.
They offer model "123" for a retail price of $750, leaving a margin of about 12%.
Let's say company A has a 2% failure rate that they cover 90%of (remember they sell to a select few).
Let's say company B has a 15% failure rate that they cover 50% of (remember, they sell to anybody).
Who has more profit at the end of the day?
How difficult is it for company A to stay alive?
Remember Crane Cams?
Compare it to The Home Depot (or any other big blob store for that matter), where will innovation come from if all the innovative companies are cheated by counterfeits and overseas junk?
The well known brands don't get there by accident.
On a side note. What does it cost you when these "cheap" parts fail? They don't pay you back for collateral damage. That is on you. I personally guarantee you it will cost more than the amount you saved by buying the cheaper (remember, we're talking $200-300 bucks here) parts.
Head gaskets and fluids will top $150 without even thinking about it, throw in any shipping, machine work or hard parts and your investment is insane.
You don't use tennis shoe laces on a pair of wingtips.
My grandfather (RIP) would have called these "plastic spurs". They look intimidating, will do the job once, but then your left with nothing.
He was an odd duck, but at the same time, a genius.
GT
