I'm not sure about the Bessa I (actually, I don't think the Heliar was even avail on that model), but I had a Bessa II w/ coated 105 Heliar, and I've owned a couple of the older Bessas w/ uncoated Heliars, and w/ Tri X and a yellow filter the shots looked close enough to say the lenses were identical. W/ color film I'm sure the coated model has more saturated colors and more contrast.
My current Bessa RF w/ uncoated Heliar outperforms my Hasselblad 80 Planar, my Rolleiflex T Tessar, and my Minolta Autocord's Rokkor, so that's some excellent company to be in. The only downside is it's a red window folder, so shooting it is slower than the cameras I mentioned. But in terms of sheer optical quality, for what I'm looking for, it can't be beat.