Yes I agree with others it takes your sewing up to another level. I actually overlock all my toile edges once they have been cut out as I find it so much nicer and easier to handle when there are no nasty threads which seem to grow as you are making a toile up. I also do the same when a garment is cut out again saving the edges from fraying.
I am in the Bernina camp - I actually have two overlockers, however one of them converts to coverstitching. Why have two you may ask. Well a few years ago I had an elderly friend whose overlocker a very old Bernina one was playing up, and she wanted a new one but felt she couldn't justify buying a new one. Well at that time I had a Bernina 1100DA which was a few years old, nothing wrong with it at at all, but I was altering some knit garments and realised that a coverstitch machine would have been really useful so went investigating. The shop I used was selling the top of the range Bernina 25000DCET an overlocker and coverstitch in one machine - at a silly price as it was their demo model, and my elderly friend bought my smaller one. Sadly my friend became terminally ill and was keen to sort her sewing room stuff out, and I agreed to have my original overlocker back and that was a relief to her. However when I collected this I found she had not even used it in the few years she had this - such a shame. So I have the best of both worlds, I tend to use the smaller one for everyday stitching, and use the bigger machine when I want something more than overlocking, i.e. chain stitching or coverstitching. These machines are not cheap, they are lovely to use, quiet and stable, and I was so lucky to be in the right place at the right time.