I was. You mean Avent yes?
So I used Avent bottles and Avent dummies. We were happy with it but I heard it's not really "natural bottle" as breast never looks like this bottle. However we used it from 2weeks old once for a time with ebf, from 3mo for every dreamfeed until 6mo, than as a only-bottle-fed-baby until 12mo.
The only problem we faced was teat vs milk. Avent offers small niddle-size holes (1-4 I guess) but with formula milk we used, the holes were being blocked as milk was too thick. We solved that easy and after size 0+ we moved to 3-flow teat Avent Natural which worked great and was ok from 5mo till the end.
Another small disadvantage - they tend to be destroyed (3-flow tears), as when you clean them thoroughly the cut on the end of the teat may get ripped off.
In general I was extremly happy with these bottles, also dummy did the job.