I have the R3A, have the 40mm/1.4, and wear glasses (nearsighted.) Around the house I will often go without the glasses, and for short distances will use the camera without glasses, but generally have the glasses on.
Without the glasses, the frame lines are pretty easily visible, but as another stated, your eye does need to be up close to the view finder. If you don't wear glasses, then I wouldn't really worry about it myself.
With glasses on, it's pretty easy to see the top frame line and the bottom markers, but I do have to move around a bit and/or press the glasses on the viewfinder to see the sides.
I too read all the discussions about it and took a while to decide between the R2A and the R3A. In the end I decided on the R3A because the 1:1 finder offered a tad bit more focusing accuracy, and since I like to shoot often in low light, figured that extra edge would be worth it to me. I sometimes forget to do it because it isn't yet automatic with me, but when I've taken the time to focus with my right eye and keep my left eye open, it actually seems faster to focus. However, it is a bit weird -- right now anyway -- to do that so sometimes I forget.
With the 50mm (Jupiter-3) lens, the frame lines are totally not an issue. I haven't had the 40mm long enough to get a feel for it, but overall so far I'm liking it and don't find it to be such a big deal that I don't always see the sides of the frame lines. Honestly, if framing is super critical to you, my personal opinion is that maybe a rangefinder isn't for you.
Actually, I try to setup and take the shot so quickly that I don't always pay attention to the frame lines anyway. (Though, I know I should be better about that!) I'm more concerned with trying to be as least disruptive and noticeable as possible, so I try not to dawdle around when I raise the camera to my eye. In fact I'm trying more and more to take the occasional shot from the waist or chest after some basic preliminary setup, like focusing at something in the same plane. (I have a LOT of practicing to do there. 😉 )