The 'Kernel' is a part of the ROM. By flashing the new ROM you choose, you will overwrite what you installed.

Do this:

nandroid backup (if you need to)
wipe data
wipe dalvik
wipe cache
flash ROM
--reboot--
setup your phone.

If you choose to flash another custom kernel, you can do it AFTER you reboot....AFTER installing the new ROM.
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Also...Install this: http://www.goodandevo.net/files/sdread/sdreadahead-512.zip

It dramatically increases the read speed to your SD Card, making pictures, videos, songs, etc load way faster. More info: here.
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I'd STRONGLY recommend the Fresh ROM. It is a slimmed down version of the Sprint ROM, not a completely different ROM....the best part? EVERYTHING WORKS!

Download: Fresh Evo 3.5.0.1 (New OTA)

I've tried many different ROM's and I keep going back...no lockups or reboots with Fresh.

 

The kernel you flashed when using Cyanogen is more than likely a kernel that works only with AOSP ROM's. Mikfroyo is a Sense based ROM, so you'll need a kernel that works with Sense. Essentially, when you flash whichever ROM you choose (I'll use Mikfroyo for the sake of the example), it'll come with a stock kernel (most Sense ROM's come with HTC kernels), that will replace the kernel you were using when you were running Cyanogen. Even if you were coming from a Sense ROM, had a kernel designed for Sense ROM's, the ROM you're flashing will have a kernel, that will replace the kernel you had at that time. So in short, you won't need to flash a different kernel after flashing Mik's, unless you'd like to overclock or would like to run a custom kernel. Hope this helps.

 

As Frenchy said, do *not* flash that kernel on a Sense ROM. Not only does it come with its own kernel (*almost* every ROM will), but it's designed specifically for that ROM and its functionality. Sometimes you can use AOSP kernels on a Sense ROM, but I wouldn't try that one. Try it with the stock kernel for a bit, and if you decide you want to overclock, or simply feel you can get better performance or battery life out of a different kernel, you'll need a Sense based kernel. The most popular is netarchy. If you want more information about kernels and what to flash, specifically, read this.

 

Short answer no. If it's not buggy, crashing, and is pretty much stable for your phone, GREAT! Many aren't that lucky.

 

the latest mikfroyo comes with the sd card speed tweek, no need to flash anything for it.

everything works on mikfroyo no freezes or reboots. but so far for this goes for all sense roms I have tried.

the mikfroyo rom pretty much comes with all the tweeks you could need. only with a stock htc kernel so no overclocking.

 

Aside from the theming being completely different, Mikfroyo is based off of a base ROM by the developer, which has a lot of junk removed from all of the system apks. It makes the ROM smaller and it loads and runs a little faster. Other than that, you can look at the changelogs and descriptions for each to see what different mods each has.

 

There's a BIG difference in speed between the 2 ROM's to me.

 

Fresh is extremely simlilar to the Sprint ROM, just a bit quicker with a bunch of Sprint apps removed.

MikFroyo is heavily themed, very few Sprint apps, and a few tools for customization.

I've been a big fan of Fresh for a long time...its been really stable. I'm playing with MikFroyo a bit now and if it goes a few days without any freezes or reboots, I'll probably make it my standard ROM.

mikfroyo's SD READ is set at 256. I've found better results with 512. I've also tried 1024 with diminished results, 512 seems to provide the best results.

 

I have to agree with frenchy....mik and myns roms both are blazing fast compared to fresh. Fresh is a good rom don't get me wrong...

Cm...wasn't for me. Even the stable versions were too buggy for my tastes


For whatever reason I did have to run the sd zip on mikfroyos latest. Not sure why.

 

Glad you're liking Mikfroyo, 4.5 is out btw if you didn't already know and can be found here:

[ROM] - [02/06/2011] - MikFroYo v4.5 - ReEngineered Sense - Still Fast. - xda-developers

Also, if you think it's pretty quick now (which it is), wait until you flash a custom kernel and overclock it!

 

Most developers will recommend that you wipe data each time. Most the time you *can* get away with not wiping data, but it can cause random issues that are hard to troubleshoot. If you're switching ROMs, you should definitely wipe data. It would be smart to just wipe data each time, even if just upgrading a ROM. That being said, just follow the developer's instructions. Some will say it's necessary, while other's won't.

As for Gingerbread, if you want to switch to an AOSP (based on google source) ROM, such as the Cyanogenmod Gingerbread betas, then you can have Gingerbread. If you're waiting for Mikfroyo (or any Sense based ROM) to get and update to Gingerbread, you're going to have to wait until HTC releases an OTA update for it. ROM developers need something to work off of.

 

I have not tried CM nightlies yet for the Evo but with the Hero, before flashing a new nightly, wiping Dalvik cache and cache was all that was needed. Is this the same for the Evo CM nightlies? Just curious

 

I think you'll be okay with those, as they aren't full on ROM updates. Somebody else who actually does that may have to chime in on that one.