Well I've answered my own question here. I bought yesterday a Soto Diffuser and it is so much better than the previous one. And I was right, the aroma it gives off is so much stronger. In fact I am so used to putting loads of oil in, it was overwhelming the aroma, so I can cut back a bit on drops I use, which is great as I'll save money. The Soto was £50.00, where the one I'm comparing was £17.00. So folks, if you can afford it, best to go for the more expensive one.
https://www.amazon.co.uk/SOTO-Aroma-...=soto+diffuser
Patrycia