like anything new in brewing, its appropriate to create like sample sizes for comparison. while stir plates are relatively new as you say, given the equal time period (say last 5-years for instance) of stir plate use compared to non stir plate use, great beers were produced (whether award winning and medal counting or not).
However, no data exists that clearly demonstrates that stir plates have improve the quality of home-brewed beer, which means that a stir plate is an unnecessary expense for most home brewers, especially brewers who are on a tight budget like I was when I first started to brew over twenty years ago.
On a different note, I just purchased a Corning 1395-5L (5000ml) media bottle to keep the Corning 1395-100 (100ml) media bottles that I use for first-level starters company.
Corning 1395-100 media bottles filled with autoclaved wort
Corning 1395-5L (the mother of all media bottles, that is, except for its bigger brother the 1395-10L)