I had the same worries as you before I bought CoD. But believe me, the sim has since put my fears to rest. Money well spent! I guess the updates that have come out since the game hit shelves had made it a hell of a lot better. And we're still not done yet: IL-2 CoD will be a WIP for quite a while! And we all expect that Oleg will soon release the MoAP: the Mother of All Patches!
Nothing changed?! No, you're wrong! Graphics are FAR better if you have the machine to push them (I do). Sounds are also WAY better: the 109 engine sounds are very realistic comparing to videos of the real thing and hearing it in person. I've never been around a real Spitfire or Hurricane, but those sound good too! The gun sounds are a bit damp, but definitely not cheesy like 1946.
Oh, and it gets better. Far better damage model, better ballistics and WAY better flight model. And when this game says "Complex Engine Management", it MEANS IT! You can control pretty much anything: the cockpits are not just gorgeous but everything is clickable (and of course, easily mapped to keys, stick axes, sliders, etc). Even your virtual pilots head has true 6DoF and "sways" and "bounces" as you fly based on physics -- and I hear it is spectacular with TrackIR!
They have corrected a ton of historical inaccuracies that never got fixed in 1946. For example, the real Bf-109's flaps where raised and lowered by turning a hand wheel near the pilot's left knee (right by the elevator trim). It was slow to use, but the flaps could be adjusted gradually with precision. In 1946 you could just push a button and switch between "flap modes", or you could rig the flaps to an axis on your stick and they would raise and lower super fast. Now they kept the option to toggle your flaps, but they deploy at realistic speeds. You're not getting any "super human" flaps in CoD! And this is just one tiny example. They've put a LOT of precision into modeling every aircraft and making flying it close as you can currently get to the real thing. I'm getting performance out of my 109 that is damn near identical to historical specs, and loving every minute of it!
Don't get me wrong, the game has bugs and problems. But so far none have wrecked my gameplay or really hurt my experience. For example, recording and playing back mission tracks can still be buggy -- your edited track might have you dropping your bombs off target when you really nailed the damn thing. But like I said, no fatal bugs have appeared on my installation. Well, once or twice the guns on my 109E-1 have kept making a shooting noise after I fired a short burst and required a reboot of the game, but it has not happened again since. That's the worst I've yet seen.