I'm the type of person who cannot stand to play Sims 3 without CC, mainly in regards to hair. So, as one might expect, I have a lot of CC.
In just hair, I have 93 (114 MB) .package files (the immense number is from having the same kind for each age), and 12 (36.4 MB) .sims3pack files. This is not taking into account NRaas mods, houses, towns, clothes, or objects, all of which I have far fewer of.

I've been seeing some things stating that Sims3Pack files are smaller than Package files, though I'm finding that hard to believe since a majority of my package files are 3-digit KB, and a majority of my sims3pack files are 4-digit.

Would it really be more beneficial to switch over? Is it even actually possible to convert package files into sims3pack files? If so, would it make any difference on the file size, or the incredible lag that I'm experiencing?

If what I'm hearing is true, but conversion is not possible, what alternatives do I have? I've already removed CC I feel I can go without (such as prosthetics, sorry Sarah) and a few clothing items.

Sims3pack files are generally more of a hassle to install, so I'd say keep the package files. The size between two files that contain different things really don't matter. I've seen files where the creator included one of each type, and they're usually close to the same size if they have the same content.

In TS3 you can combine several package files into one big package file, to reduce lag. Haven't done it myself, but I know it can be done. Maybe look up a tutorial on it?

And finally, the size fo your amount of CC always counts. The less, the better your game will run. Having lots of CC will cause lag, even with all the tricks in the book applied.

I don't mind hassling with installation. I'm fine with waiting half an hour for a collection of sim3pack files to install, if it means I don't have to wait an hour for my game to even open, plus another four to open CAS and make a new sim.

So..just to make certain I understand the above post: Is the assertion being made that package files may be connected to slow game loading and slow opening of CAS? Because of size diffys?
I have a feeling the slow loading may be due to amount of cc, not file format..but would be interested in knowing if anyone has tested package files versus sim3packs

I'm interested because I try to avoid installing things through the launcher..because it is so slow and I like to easily move files in and out for testing without waiting for launcher to cooperate.
My game loads quickly and i have no appreciable lag in opening CAS and making sims.
I have about 270 ish files of cc in my mods folder as package files. No problems . Perhaps not anywhere near as much as the OP tho..

Can others shed light on this matter please? Has anyone tested if Sim3Pack files are better for installing any cc other than patterns? (that has already been explained to me)
I do see that a lot of cc makers only offer sims3pack files and so often times forgo using some cc because i so detest the launcher.

Edited because apparently, i didn't read the OP thoroughly.

It's been a long time since I converted most of my sims3packs into package files and merged these into 5 big chunks, but I seem to remember that when I loaded my games afterwards CAS was slightly slower when I opened it first but as soon as it was loaded switching between categories became noticeably faster.

Now when it comes to the game itself loading I think the biggest resource hogs are the script and core mods and not additional items, so I don't think that there's much difference between sims3pack content and packages.

By definition, sims3packs are always bigger because they have a load of pointless wrapper code that package files don't. The difference is generally minimal though, like a few lb.

Once you've installed a sims3pack it gets converted to a merged package, so at that point any difference between the two formats should disappear, and you just have the general usability/hassle factors to think about.