Actually Proton is not really that bad. It still have some quality issue, but to be fair, they do improve a lot since then.
In the 3 given choice, I agree that Exora cannot be directly compared with the other two, not in quality, image nor equipment, but the price vary a lot too. So count in these factor, Proton can actually be a good choice. Furthermore, you have to measure in the maintenance too. Proton's parts are not cheap actually (original parts that is), but they are always available.