EF 50mm f/2.5 Compact Macro for people and landscape

Paulo,
I do own this lens, but can't recall using it in the last 5 years, for several reasons (which I'll get to in a moment).

Though I don't own either of the other two 50mm lenses you mention, I would expect the f/1.4 to have the best image quality of the three you list, though I wouldn't expect a big difference from the f/1.8. Hopefully some other folks who have experience with these two lenses will provide some more detailed comments.

As to why I haven't used my f/2.5 compact macro in a long time, there are two main reasons and a number of secondary reasons, which may not apply to you at all.

First, I'm using APS-C format DSLRs, for which a "normal" focal length is around 28mm. I find that most of my photos are made with focal lengths either in the range of ultra-wide-angle (10mm for this format) to about normal (28mm-35mm), or telephoto (100mm and longer); I just don't find myself using the 35-100mm range very often.

Second, as a macro lens (and I do a fair bit of macro work) the f/2.5 compact macro has one important limitation: working distance. At its maximum magnification of 1:2, the front of the lens is only 2 inches from the subject. Add a 25mm extension tube to get to 1:1 and the working distance is down to 1 inch. This just doesn't work for most insects and animals - they won't tolerate that close approach. And even for subjects that can't move on their own, like plants or rocks, lighting is difficult with the lens that close to the subject. I much prefer the greater working distance afforded by a longer focal length macro lens; I now use a Sigma 150mm f/2.8 macro, but have obtained good results (and even greater working distance) with 300mm and 400mm zooms together with high quality 2-element diopters and extension tubes.

Several secondary drawbacks (in my opinion) of the f/2.5 compact macro are due to the focus mechanism: it's a front-focus, external extension design. This makes it very slow to auto-focus (for non-macro work). (On the other hand, it has very fine control for manual focus.) It also means the front of the lens (the filter ring) rotates with focus, which makes use of a polarizing filter or split ND filter (again, for non-macro use) a real exercise in frustration. And lastly, for macro work, the external extension means that changing focus changes the magnification (dramatically). It's best to set up with a focus rail, set the magnification you want on the lens focus ring, then focus with the rail.

I hope my comments are helpful, and also that others will offer some other viewpoints.