If you're willing to spend the money for a quality airless sprayer you'll be pleasantly surprised. The cheap ones aren't worth the time. Here in the U.S. the brand of choice, at least for me, is Campbell-Hausfield. Wagner makes a good unit but they also make cheap ones. A good unit here will cost between $250 and $550. They can go as high as $2200, however.
They are easy to use, handle the thickest of paints and literally no over-spray. I carry an aluminimu venitian window blind slat as an aid in painting next to windows or door frames. The unit I have will spray a line right up to within 1/2 inch of the frame with no overspray.
No thinning required.
They do require scrupulous cleaning when finished, however. Running lots of soapy, warm water thorugh the hose and pump. rinsing with clear water and using a special lubricant for the pump before storing.
The unit handles oil based paints equally well.
Don't go cheap on buying enough hose. Our house is neatry 40 feet high on one exterior wall so it's nice to have enough hose not to have to climb down from the scafollding.
What took me 3 to 4 days to paint with brush on wood siding now takes about 6 hours including clean-up.
Good luck!