Hi,
Yeh - it can be frustrating alright. But they do give you extra yardage, and with practice you'll get better.
These clubs in themselves may only give you 5, 10 20 metres max extra, but thats all you need and with that you will shave a few shots off your round.
I shot a 73 the other day - so it gives you hope. The challenge is to break Par - now that'll be good.
Cheers
Doug