I like the proposal. I don't know what would make a stadium "unique" - unlike baseball, every football field has identical dimensions. Obviously a stadium like Seattle's holds the noise well, but that tends to take care of itself when a good team is on the field. Apart from that, seems like good sightlines, good sound system, good and large video boards, closeness of fans to the field, and good traffic flow and concessions are the main variables. It's hard to evaluate something like that. (Just ask the 49ers, with their billion-plus Levi's Stadium; they haven't played well there; there are turf issues; the neighborhood hasn't been thrilled with it; and it's 45 miles from downtown San Francisco.)
What I like here is the following: 1. It virtually overhangs the Mississippi River - great views from inside, and especially from outside. 2. It's halfway between the two anchors of the St. Louis skyline - the Gateway Arch; and the Stan Musial Bridge. 3. It's open air - St. Louis has moderate weather, so shouldn't be an issue in 80-90% of games. 4. It's surrounded by dedicated parking spaces - similar to Arrowhead Stadium in Kansas City, which has one of the best tailgating/gameday experiences in the NFL. 5. It continues and adds to the current redevelopment plan of St. Louis - the "city/arch/river" plan, which creates green space, instead of Interstate Highways - from downtown to the River and the Arch. 6. It permits repurposing of the Edward Jones Dome to be fully dedicated as part of the convention center; in effect developing two public venues, rather than one. 7. It doesn't require new tax proposals. 8. It still is easily accessible to Lumiere Place, redevelopment of downtown, etc.; and it would only be a small part of that redevelopment, already in progress - rather than an anchor of such redevelopment.
It would result in a downtown running from the River/Arch/Stadium at the east, to Tucker/I-70 to the west; and from Busch Stadium at the south, to the Stan Musial Bridge to the north. Finally St. Louis would make proper use of it's most compelling natural resource, the Mississippi River; similar to Chicago's use of the Lakefront.
The football stadium/baseball stadium would be similar to Pittsburgh, with both the ballpark and Heinz Field hard on the River. I'm intrigued.
I think the approach is wise, too. Maybe St. Louis isn't LA, but it's - in my opinion - clearly a qualified NFL city.