Third and fourth are going swell !
The first one is a long series of bewildering tests, skill jumps, practise, cussing, pain etc.
As we started the 8 after building the 7, things were familiar from the get go. Your skill sets for deburring, priming (sorry, I said it) riveting and assembling were already there, but still there were changes and different sequences which still challenged.
The 12's.......
Meccano becomes Airfix
Gone are the 3 view plans, the standard engineers prints and in comes isometric drawings which were a revelation. The instructions still need reading and reading and then in some rare cases amending, but it was a quantum leap forward.
The 14 is similar and as the 12's leave our shop later this year, my buddy will slide the 14 fuselage in for us to finish while he does the wings.
It gets easier. You get more proficient and comfortable with your unfupping skills when things don't quite go right
Your tolerances stay the same, but hopefully your pragmatic approach gets better.
If you are getting close to the end of your 14, remember - if you go backwards, the prints will regress and need interpretation. If you choose to go back to an 8 or similar, the build sequence will not be so proscribed as it is with the 12's, 14 and presumably the 10.
Whatever you choose, it will be easier, more difficult, less frustrating, more challenging but above all - cheaper than therapy