I enjoy building them while listening to podcasts, at least once I've ironed out as many kinks as I can... With Tower Bridge I had to move the piles because the autoplacer put the colours so far from where they were needed (especially the most used colours) that I ended up having to hand place them all, usually I don't care so much but because this was such a large and, especially, long build the autoplacer just wasn't set up for it!
I enjoy the building ones the most so they are probably optimised the best, like changing the standard to only placing doors and windows once the top block is also in place made it harder for people to block themselves off from the stairs (assuming they didn't have flight) though later I also reworked them to have the door mostly open (though that doesn't always help in some builds with tight spaces!) I also have a lot of nostalgia for the old space sets since that's what a lot of what I played with as a kid, though also some technic but those sets are a lot more work to transfer across and the requests I received were for simpler builds (which those are not, especially from a lego character's perspective!) - that's also the reason for the large number of small easy builds (Lego is a children's toy (too ;) after all! :D
Oh, I should apologise for the Marina Bay Sands model... I have yet to complete the build order for it - the small model buildings are probably the hardest ones to do as they seem to have been optimised for block count and compressing as much as possible into a small space which means they have huge numbers of blocks for such small pieces as well as specialised pieces used in strange ways to get a good match to the original buildings in a small space... they are kinds impressive in a way but the build order is really hard to organise because base pieces are often rotated ninety-degrees to build the sides of the buildings which means I have to rotate the build progression with them so it make sense but then I have to make sure that higher pieces don't overlap with lower pieces in a different rotation as well as make it hard for the player to place pieces that block their view of where unplaced pieces go (something I find frustrating, hence caring about it!) The Marina Bay Sands model has multiple rotations with many possibilities for overlaps and hiding pieces that are not structural and therefore might not yet be built hence it isn't finished yet... and I have to admit it might be a while before I get a chance to finish it - I don't have much quiet time to have the time to build the model in my head and then work out the potential problem points... I'll check my personal git to see how far I am from completion but I think the one in the public git is the latest.
In case it is of interest I'll mention that the majority of the ones I currently have on my slate are larger figure-scale buildings, a few more space ones and a few fun builds like the medieval ones and the "multiple models from one set" ones (e.g. the three beach huts and the seasonal houses). In summer I might get a chance to work on some technic ones for myself! :)
Edit: P.S. Do you have any other block style games you could recommend? They are a firm favourite here, Bricksperience included despite it's lack of development.