I made a side-by-side SG 1.055 batch with same amount of M27 Belgian Ale and M29 French Saison and I came to feel that they are not the same strain. M27 was a few months older than the M29, but they were held in the fridge side-by-side. Both yeasts were added to a very basic wort (pilsner+wheat+magnum), inoculated at 20C, I set the fermentor for 25C and no limits up.
After only 4 hours the M29 showed explosive activity, literally boiled like a lava lamp for two days with it's temperature free-rised to 31C. Thick 1" krausen formed, highly unusual as I tend to have more stealthy krausens. Never ever seen such epic fermentation, it was a scary and a marvellous sight.
M27 took (the usual) 24 hours to show signs of fermentation, formed a solid 1/2" krausen and its temp rose only up to 28C. Nothing out of ordinary. Both yeasts were rehydrated in boiled water cooled down to 20C.
After two weeks both received FG (1.005), M29 was faster and ready at 11th day. All two beers showed a layer of glycerine that sticked to the side of the china espresso-cup I used to take tasting samples.
Side by side the beer with M29 had a more inviting smell, sweet, bready, characteristic yeasty scent without any high notes, while the M27 was more neutral. Neither of them made any high-alcohol smell, and all too were pretty dry and round taste.
Starter made from M29 had no different smell than the beer, no big news as no aroma-hops were used, only some first wort Magnum for 28 IBU.
Both beers were converted to ginger saisons by bottling them with spiced syrup, 3.6 CO2 in heavy champagne-bottles. Now I mixed the M29 with some harvested Dupont and I will compare it later with M29. I think both M27 and M29 are great strains, anyone brews saisons or - like me - have a love for dry beer should have a pocket or two in the fridge-door. They can save the day if a finicky strain decides to strike instead finishing the job. I was not that lucky with Belle Saison so far but thats another story and could be because the yeast was handled badly in the HBS.