Flash,
The reality is that no one machine can do everything. Depending on the environment a cheep machine my outperform a high end piece of equipment.
When I buy equipment I conciser the day to day requirements and buy a task specific unit.
Your environment may be different but I would guess you are trying to do to many different things with one machine.
Today I am replacing zippers in some motorcycle jumpsuits I set up three machines for this project.
A flat bed for replacing the hook and loop fasteners that the manufacture installed through the shell and the lining.
Two post bed machines one with 69 nylon for basting the linings to the zippers.
The other for stitching the zippers through the shell with 138 nylon top and bottom.
Each machine is set up for the task at hand. I spend a few min. making sure the equipment is properly calibrated.
Proper needle selection, stitch length, stitch quality, thread and ergonomics. all factor in to setting up a good work environment.
I could get away with one machine but I would have to sew in batches that would create work flow inefficiency. ie. baste all the zippers to the linings then change thread and stitch the zippers to the shells.
The unfortunate reality is that smaller shops have a limited amount of resources and may have to settle with a less than optimal configuration.
I would recommend looking closely at your production needs and try to find trends in your workflow. This way you can identify tasks that my be best served with a task specific equipment choice.
Best of luck,
Al
PS.You can't lose with Cobra Steve and The leather Machine company.