I just wanted to stop by and say that I tried my hand at this recipe not too long ago, and had my second tasting last night, 3 weeks after bottling. It's quite nice, although the carb did get a bit cold during fermentation as the temperature here dropped in early October.
In my case, the banana almost entirely resides in the aroma. If I hold my nose and take a drink I can't taste it whatsoever. I get a whiff of it as I take a swig, and then again after the swallow. The taste profile actually has the slightest bitterness to it followed by some citrus-y notes, almost a banana peel type flavor. The mouthfeel was very nice and smooth.
What I think contributed to this a bit is that the bananas that went into the primary were fairly ripe before they were boiled and pitched, but the secondary bananas barely had any ripening spots on the outside of the peels when they went into their boil. Likewise, the ones that went into the primary were almost entirely metabolized by the time I racked, and in the secondary much less so.
I also took a note from KeeptheDrive, and added 3 vanilla beans to the secondary carb hoping to get a bit of secondary or tersiary flavor from them which did not end up coming through. I split the beans lengthwise and then cut them into thirds before pitching into the secondary during the rack.
I know this is a fairly old thread, but any tips would be appreciated on how to get the banana flavor to come through more. It didn't come out quite as I had expected, but it was still delicious and I plan to make another attempt at this sometime in the future when the weather turns warm again. As it is, It's definitely a beer I could see myself sitting and drinking all night during the summer, but I feel it would be a tad more enjoyable if the banana flavor was a bit more present.