[Galaxy S I9000 Android Development] Kaik541:
so, to people complaining about speed, I only have a few things to say (and some of it has been said before) but I'm just getting tired of hearing the bickering.

This ROM is still very immature and under heavy development for ALL CyanogenMod devices, so small issues are likely to crop up. I get the occasional stutter even on my Nexus 7 in certain circumstances, and that's the device that was specifically designed FOR Jellybean.

The device is starting to show it's age, when Samsung launched the SGS1 devices, it was already running and designed for an outdated OS (Eclair) when everyone else was reveling in Froyo. Samsung could not have predicted the growth of android to Ice Cream Sandwich (or beyond to Jellybean and what may come after). Being spec'ed very similar to the Nexus One (which also has no official support for anything beyond Gingerbread, and it's the first "true Google" device), it's not surprising that the device won't run "the latest and greatest from Google" in the best way possible.

While being similar to the Nexus S, a lot of people think that means we're experiencing the software the same as users on the Nexus S, which just couldn't be further from the truth. Google worked with Samsung to change so many things that most of what we have in common with them is the SoC, and not much else. Sure, we stole their MTD driver in hopes of getting a speed boost from it (which we did, at the risk of making a lot of things incompatible from the stock ROM we were used to--who actually remembers you could do "adb reboot download" when you bought the device?) and we borrow from their kernel, camera (I think), and graphics libraries where we can, but I can guarantee you that a Nexus S would look at our phones like the sad little cousin who tries really hard but never quite measures up.

Pawitp decided that we're moving away from the /datadata partition. This has been an issue since Gingerbread because users couldn't be bothered to understand why the device was showing "low storage space" warnings when the Internal Storage still seemed very open. A lot of users figured it out and moved on with life and managed their app choices with a lot more scrutiny, some people remained confused for months. This eliminates the hassle for everyone though, no more checking space in a place that doesn't seem intuitive (huzzah!). The trade-off being of course that we're putting it right back onto the crappy NAND that made the stock ROM's so god-awful slow (booo!).

While Project Butter is awesome, it's not the make-or-break thing lots of you make it out to be. It seems we have this issue literally every time there's a new Android version. It was the same thing that happened with Ice Cream Sandwich when everyone heard "the GPU accelerates the whole UI" and it seemed like the magic cure-all for our issues (with absolutely no evidence to back this theory up). It makes things better, but it won't suddenly turn our phones into the magical unicorns we all dream of at night.

CM9 will continue to improve and hopefully the user experience for our devices will get better, too. But hedging on that happening would be like betting all your money on red at a Blackjack table... everyone's going to assume you're drunk. I'm not saying to give up, but maybe just lower your expectations for a device that's recently gone past it's two-year-anniversary. You'd laugh at anyone still using an iPhone 3GS or a Motorola Droid today, well our phone suffered some serious limitations imposed by Samsung's internal processes that made those devices pretty much as good as ours out of the box. CM always tries to put the manufacturers to shame in what options we provide and the pace of our upgrade schedule, but that doesn't always mean we're smarter than them (hindsight makes a huge difference in life). Were we all upset when Samsung refused to have an official update to ICS? A little, but if you really think about it, would you really have enjoyed that user experience? I'm not saying they were right to more or less ignore the device's upgrade path, but that they probably had a good reason for it and I can't really blame them for it.

tl;dr - This device is old and is showing it, it may not run the software the way you expect it to. If it doesn't meet up to your expectations, please feel free to revert back to Gingerbread (CM7 or stock-based) or Ice Cream Sandwich (CM9) and see if that meets your hopes as well. If not, it may be time to look into buying a new phone.