I have learned all lasers are different. Based on the frequency of the unit. Some things work well at the diode range, I think it’s about 450 nm, CO2 is about 10.6 um. They effect material differently as the frequency changes. That said…
The CO2 does amazing stuff for the price. If you want to dump 7K for a ‘cheap’ fiber laser, but still out of the range of most.
The other consideration, is the device (actual laser module ‘head’) you have is mostly heat sink. If you could double the input power you’d have a large increase in the size of the cooling area. Probably more than double the current head size and weight to deal with the losses inherent in the system. Increase in mass of the head changes machine operation, maybe to a point where it fails to move it properly.
Your type of machine is about maxed out for any reasonable work.
I purchased a China Blue and in a few days I’ll have had it a month. I’ve already rewired parts of it and replaced the head. I purchased it to learn on…
So what do you want to do, is the best question you can answer. Then find the device that fits the bill.
Both lasers I have, have been a joy/headache and learning experience. I’ll keep both and find another type down the road, if affordable.
Best of luck