I planted one each of Carmine Jewel, Cupid, Juliet and Romeo in May 2011. They are now about 6 feet tall -- Romeo probably closer to 7 feet, others all a bit under 6 feet. All the bushes have fruited for me the past two years, but I have yet to see the heavy crops like the U of Sask. reports, despite having heavy blooming. Not sure why, seem to be lots of bees at pollination. Carmine Jewel has given the most cherries, but so far only a pound or two the past 2 years. I am located about 300 miles due west of where these cherries were developed, in zone 3a.
Juliet is the best tasting (least tart) of my cherries, Cupid isn't far behind and has the largest cherries. Romeo is getting too tart for fresh eating for me, and Carmine Jewel is downright sour and has the smallest cherries, but has been the best producer.
Cupid is the only bush that has suckered so far, and those suckers are very close to the main plant, basically growing up through the canopy of the original bush. I have not tried digging out any of these suckers.
In 2015, peak bloom time for these cherries for me was: Juliet - May 15; Romeo - May 20; Carmine Jewel - May 21; Cupid - May 23.