A craftsman cabinet builder could probably do a better job using a screwdriver and knife than a layman could using quality chisels and saw as it’s in the knowledge, experience and skill of the person using the tools...
The dent puller may be a “bit flimsy and cheap looking” but much of the outcome is based on the knowledge, experiance and skill of the operator*. I’ve heard the most critical part of the tool set is the quality of the glue’s composition, too weak and the stud will break free before it should and too strong and it may pull paint off the panel (also the case if the paint is non factory or soft, which is probably of more concern to you given the painting you've done to your ute)...
The only way to know how good the tool is and more importantly how you’d go with using it is to buy one and try your hand at dent pulling.
( * no disrespect meant towards Mick HHH
)