It really depends on how loose you get with the definition of CGI. I don't like relying on other people for things I can't do myself, I don't ever want to end up with a project I can't complete because some effects work need to be done where I can't find someone to do it at the quality I want or do it myself.
But I digitally add a lot of stuff into my shots via After Effects with digital composition. I think maybe 50% to 75% of the shots in my current project feature digital effects. On of the very early shots I did was a cliff side beach, this is how it looked while I shot it, and after it was done I put blue base plates every ware they were not seen in the shot, so it was still actual LEGO, but they were moved and cloned to fill the scene, then I mask out the floating rig for the blimp next and the last thing I did was animate about 5-7 waves on the beach. I only animated each wave once but in After Effects I turned them into loops so it looks like they were constantly lapping up on the beach. I consider stuff like that CGI, does everyone else?
I've seen members post that they -don't use effects except masking- as if masking is not an effect, and maybe it's because I use masking so excessively and they are not but it is still a computer generated effect (unless they are using optical composition, ha, ha, but lets be real, they are not.)
One of my most extreme use of composited layers is this shot, in that shot I have 3 layers of pedestrians because I just didn't want to animate 14 minifigs all walking in different directions at once plus something like 9-11 layers of cars moving on the street. I animated each can separately because I wanted to create some real motion blur and while it does look good, in retrospect, I would have preferred to add digital motion blur as having a clean copy of each car would make composition easier. (And I did use digital motion blur in a close up in the following shot and the effects ultimately are interchangeable, no one will know that one was real and the other was fake) It really would make my life easier if I had done all the minifig animation in one take but I am not the greatest animator and I can't keep track of that many minifigs at once, as it was there were mistakes and issues I over looked (but I found I could cover most of those up with passing cars) but I don't think I could have created the illusion of a large city without the intense amount composition.
Onto the topic of 'fixing stuff in post' I am super guilty of this. Sometimes I will get the animation I want out of a minifig only to find I bumped some background prop, if the scene is long enough that I don't want to reshoot I will paint the prop out of the shot digitally and comp a static image of that prop over the painted out section. The computer consoles in this shot were super problimatic and I had already shot the scene around 3 or 4 times, so I digitally removed them and then added them right back in and got the shot I wanted, no one that has seen the footage is even aware of this. And that is all that maters to me, I want my shots to look like they were created on camera, but if I have to use After Effects so be it, as long as it still blends well with the film.
I think things like lens flare or explosions that have been added in digitally need at least some in camera effect to make them blend better, like shining a light on a minifig that is firing a gun, if you are adding a gun flash digital and the real set lights up every time it happens it's not going to pull people out of the film.
As far as digitally generated bricks go, if I could created brick based special effects like are featured in the LEGO Movie I would, I wish I could create brick-based water effects and composite that into my shots but all of my 3D water effects test I have done are untimely very disappointing and I wouldn't include them into one of my films. It's really only a matter of if the effects blend well with the film, if it does go for it, if they don't try using a different technique for your effect.