After trying many diffusers for Steam-Distilled Essential Oils and Hydrosol water,
We got to the following conclusions :

The best diffusers are ones that use heat, powered by electricity, using a light which you control the intensity of using a butten. This diffuser is excellent for our essential oils and our essential-oil-rich hydrosols, as the smell spreads quickly, and gets very fragrant and strong.

Pro-tip It helps cover the smell of garlic, for example, due to cooking. For as a mom, whenever I have to cook at the workplace, I always had the issue of having the office smell like chicken, meat or oil. Now, I usually turn my diffuser on before I cook, and leave it for 30 minutes after cooking. Voila! And now the office is not filled with the smell of food and I do not have to open all the windows. -Amina Al-Ramadnah

You just have to replace the oil or hydrosol every two hours, that is if you have put the diffuser on the highest setting. And trust us, the smell is amazing.

The new incense burners spread the tiny droplets of pure essential oil into the atmosphere.
This feature is called Nanotechnology and does not need any heat source. It can also be charged with a mobile charger.

It is only suitable for our concentrated pure essential oils. These diffusers are more expensive, but the essential oil stays for a longer time, as each time, the atoms of oil are sprayed into the air over a long time. Over time… the beautiful notes of oil spread in the room. In spite of that, it does not cover the strong unwanted smells of a room. So, we use this diffuser in our product showrooms and exhibitions. It is also traditionally used in luxurious hotel lobbies and clubs.