Weed eater

which one is best doing grass edging

best to possibly get a edger. In regards weedeaters when i was looking several shops (proper lawn shops) said get a straight shaft as they have a proper gear box and the curved shaft are really entry level and only have a cable driving them with a square drive on the end

A proper known quality brand.

If it’s around home get a entry level shindaiwa. It’s nit expensive and won’t break down like the Bunnings crap. They all need servicing however their is no one to service the Bunnings crap so your lawn shop guys are 5he way to go. If the echo is your price range then that will be fine around home…the bent shaft are so much more a challenge to get a straight cut

Bought a "Quality" Stihl FS38 and it would not run properly upside down to do the vertical cut to do the edges. Fuel tank design is not good enough to supply fuel to the engine. Australian and NZ forums agree with this.
Not sure if the Husqvarna equivalent would be any better as the fuel tank looks the same.
I cut the fuel cap lanyard and pulled the big plastic penny washer out of the tank as I suspected it was interfering with the tank clunk weight pick up.
Seems to run better.
The Stihl shop said that they put a heavier filter pick up in the tank for another customer so it must be a common issue.
I prefer the bent shaft as you can see what you are doing when vertical edging compared to a straight shaft.

If you're just doing edges,its physically easier using a bent shaft because of the angles

I have found that is true too!

Cable drive is ok for a string line, i have two quite old models which are a bit temperamental but i can sort them out. The main hing 'i think' you'll notice is you'll find muscles you didn't know you had--holding it t the right angle & trying to 'not' go too deep or steep--things like that. Plus you're liable to get fumed out by the exhaust if you have it tilted very steeply. Trial & error. What i've been doing for a while is speed the idle up quite high & then don't need to operate the throttle lever except if the going gets real tough. Makes it easier on the trigger finger muscles. I've been using one of mine for probably 25 years but if i leave it sitting for a couple of years it ends up needing a carburetor diaphragm kit as go hard & become a pain to keep running right. Think both mine are Ryobi [too cold to go & look]. Years ago [about 25 years] i had an electric one [plug in not battery] & was ok for while but ended up burning out the motor. Would start off ok then drop to about half power. Put up with it for a while till SMOKE! . Sorry if none of that's much help but be nice to know the outcome in the end. Here's a thought, ask the shop if they have a demo model, maybe both bent & straight shaft to take home for a play. Would have to be a 'proper mower shop' not a DIY type shop. Or hire one--then the other--for an hour or two each.