I need a new line trimmer for the yard.

I am tired of the cycle of buying a $150-$200 2 stroke from Bunnings, only for it to be useless after a couple of years.

My yard is not big, but there is a lot of hard edging (concrete & pavers). I would like something that can use a fairly heavy line, so that I am not refilling the head every 15 minutes.

My must haves are:

Easy to start (if petrol)
A tough line head, because they wear out when made from cheap plastic
Fairly quiet
Head must be easy to reload
Blades prob are no good - as there are a lot of pop up sprinkler heads around the edges.

I don't really mind 2 stroke or 4 stroke, or battery (if it has some grunt and can last 30 mins of operation).

Does anyone have any suggestions or want to recommend the one they use?