New BFP owner here.
No problem with using the stock tips. I went initially with the Large ones. The fit test showed they were fine. I could feel the large tips in my ear cavity, and although with no discomfort, I figured going to the medium tips would be even better as long as they passed the fit test. I tried them but despite the fit test coming out OK the majority of times, I ended up retaining the large tip in my left ear and a medium in the right. Comfort is no issue at all. I find the wings don't even touch the inside of my ears no matter the position. The tips are the only thing holding the buds in my ears.
As far as sound quality, I really have not much to compare them to other than a pair of RHA MA 750s I've had for several years that the BFPs are replacing. I always used Comply tips in the RHAs but I have lost any love I ever had for Comply. They are great if fit and seal are an issue but I got tired of feeling them in my ear and how they don't have the same quality and durability of the past. IMO, they are no longer worth anywhere near the money they ask for them. (not that they've ever been inexpensive anyway) With the stock tips I think the sound quality is great. It's hard to compare the two since the BFPs are airy and the RHAs feel sealed by comparison due to the Comply tips. I mean, what do you expect from earbuds anyway? I have any number of serious headphones at home with dedicated HP amps and DACs in my system. I sure wouldn't use the BFPs at home when I can use what I have there.
I have one small issue I'll resolve. Because they fit so well and comfortably in my ears, it's almost like there is nothing there at all. I always find myself touching the buds, like they have fallen out, and hitting the controls, pausing the music. I haven't spent enough time with them to determine how to operate them so I guess I'll need to pull out the literature and figure that out. Currently I have them set to lower and raise the volume but I'm thinking I'll switch that out since I'm used to reaching in my pocket to my phone or going to my AW for volume changes.
Overall, at almost a week in, I'm quite happy with them. S