You should try the PAL 4x 1080p tweak if you’re using PAL, that way you’re not really losing anything from the image other than 18 lines (which are usually blank on PAL anyway). I noted it here some time ago. It might be useful for many PAL systems which output 288p.
If you use 1080p in 5x for PAL, you lose about 72 lines (288 x 5 = 1440 – 1080 = 360 / 5 = 72), which is a lot worse than only 18 (288 x 4 = 1152, though we reduce this to 270 which equals 1080 so it will scale nicely. Since 1080 / 4 = 270, and the full image should be 288, 288 – 270 = 18). This is much better for PAL, assuming your TV can force 4:3. If not, Harrumph found a tweak for this method to make it output 1440×1080 instead of 1920×1080, though your mileage may vary with this one as not all displays will accept it.