I wouldn't necessarily say it is a matter of preference. The Speed Feed is objectively better than the Glockmeister plug, but only slightly. It would be up to the individual to decide if the "more better" is worth more money.
I got my Glock 19 models in the mail today so snapped some pictures while I was installing them.
This picture shows the installed speed feed (Glock 45) on the left next to a Glockmeister plug (Glock 19) on the right.
The ramp in the back gives you quite a bit more distance towards the back of the grip where the mag will still be funneled into position. The Glockmeister doesn't necessarily impede the magazine should it contact in that area and it will still slide forward, but it doesn't push it 'in" to the same degree. I haven't ever had issues missing with mags in that specific direction where it wasn't still close enough to go home, but it IS an improvement.
You can also see that the Speed Feed has a more precise fit. Once installed, there is no play at all where the Glockmeister does have a little wiggle. I don't think this really has any affect on function, but the tighter tolerances are nice considering the higher price.
The next photo shows each pistol (in the same order) with a flush magazine inserted.
You can see that the Speed Feed provides a lot more space for you to get your thumb in to strip a stuck mag, which in my opinion is the biggest improvement.
The next two photos show how much of my thumb I'm able to get into the gap to grab the magazine.
Speed Feed:
Glockmeister:
Is using the Glockmeister instead of the Speed Feed going to get you killed or make you lose a match? Definitely not. Should you ditch Glockmeister plugs that you already have to replace them with these? Probably not since you already have a workable solution. Would I recommend someone who is buying for the first time to spend the little extra and get this instead of the Glocmeister? Definitely.
I do share your concerns with CHPWS as a company, and that is why I waited quite a while to buy them. I purchased mine from Big Tex since I wouldn't be stuck with CHPWS's crappy customer service if something went wrong or I didn't like them. Unfortunately, I did have an issue but they got it resolved easily and quickly. There is zero chance I'd send CHPWS one of my guns/slides for them to perform work on, but I don't have a problem giving them money for innovative products as long as I know I'll be taken care of if something isn't right.