So, I hadn't cleaned my computer for like, many months and it was really dirty and dusty lol. I decided to clean the whole thing and apply new thermal paste. See for yourself, both are at same ambient temperatures. Take a look at the fan speed especially. (It's dropped by 1 more degree and fan speed is a bit lower )
I´ve seen greater effects but you did good. I have easy removable dust filters in the front of my case on two fans. After a week you can´t see the fans no more with all the dust it gathers. I don´t even know how a case without dust filters would look like after a few months, it´s kind of scary for me. As for the internal hardware i find once a month cleaning to be enough.
Yeah well my case doesn't get that dusty tbh, it was messy, but definitely not the worst I've seen. I also have dust filters on in take fans.
Yes I have cleaned mine 2 times within a few months (Last time i cleaned it there was a layer of lint over the Power Supply fins! (Intake) among other places (Not as much though)) It IS most definetly good to keep your tower clean!! Its amazing how much stuff gets in there!! (DO WE BREATHE THAT CRAP?? (I hate to think about it but ya gotta wonder))
The current case im using the Antec 1200 has dust filters in the front so it catches 99% of dust. The amount of dust that these filters catch means that i will certainly use dust filters in any cases that i use in th future as dust is one of the biggest culprits of increased heat/damaged hardware.
My case has no dust covers, nothing at all. Also, the front USB ports are broken and there are empty fan vents so its easy for dust to come in. I cleaned mine this morning. Too bad i didn't take pictures or i'd have shown you. It even had cobwebs inside. I blew the dust away with a vacuum cleaner, it was so bad that i had to wear a handkerchief over my nose lol. Temps are down by almost 5 degrees on an average.
Try using compressed air next time instead of a vacuum. I have taken mine apart twice in the last 2 months and its always been full of dust!