I didn't see any other reviews for 2015, so I thought I would be brief and add mine.

Same in 2015:
Great expo at Chaifetz Arena - I am biased because I work at the expo every year, but I heard many comments about how quick and easy it was.
Same great finish line food, featuring local eateries and a wide range of salty and sweet treats.
Great volunteer support and crowd support.

New in 2015:
New course brings you over two different bridges into Illinois and back. Safety tip: I would advise against running on the shoulders of either bridge. Believe it or not, you could feel the bounce of the runners on both bridges and another runner in my training group and I almost fell coming back into Missouri because the bouncing bridge nearly caused our legs to buckle underneath us. We both stopped and walked if off, but just a warning. The feeling of the pavement bouncing under your feet was very bizarre and more pronounced on the shoulders of the road.
The t-shirts were gender specific but we had MANY complaints that the women's shirts ran very small.
I believe the course was flatter this year, but I used the word "flatter" and not "flat." I live in the St. Louis area, yet I forget how hilly downtown really is.
The welcome squad as we crossed into East St. Louis was probably my favorite along the whole course.

I said I would be brief, but overall I would recommend the race for both locals and out-of-towners.
My full review: http://willrunforamedal.blogspot.com/2015/04/go-st-louis-half-marathon-race-recap.html