I think the last laptop I bought for myself was 2006. At the time I bought a nice one and I do still use it sometimes. I can record 16 24 bit tracks indefinitely on it.
I also have a USB ssd with Ubuntu studio on it and I can boot most computers to that. This saves me the trouble of having to bring my own computer. I have done large multitrack live recordings using that ssd and Linux on random laptops. I can use any handy laptop with the ssd and it works like it is my personal computer with all my programs.
For home recording, I have a rack mountable studio-cat which is getting old now. Jim probably knows how old. Six years? More? My only issue is not the fault of the computer. I like to use rapture pro with high voice counts and this can drive one processor to the point of glitching.
I don't use sonar in the field. There are two reasons.
1. If a dropout occurs sonar doesn't recover and keep going. This is fine in the studio but when recording and mixing a band live, this is unacceptable. There are too many ways a recording can be ruined. Adding fx live etc.
2. Rapture pro entices me. I have so much fun with it I would love to take it out with me. But it is too hard to bypass. I can't bypass it with act. I've given up. And at times when I'm playing, it must be bypassed or it will go glitchy. I can bypass it by touching the touch screen but this is hardly a performance level solution.
So i have never needed to put my studio-cat rack-ears on. I have manually carried it out unracked maybe 4 times to do remote web broadcasts.
For field recordings, I tend to use rme digicheck [definite favorite] or mixbus with my rme in class compliant mode
It is nowhere on my list to buy more computer hardware.