iPhone 4, best OS to use while UNLOCKED?

[dmx434343]

Hello, I recently purchased an iPhone 4 (used) which has OS 4.00

I was wondering what would be the benifits of upgrading to .01 .02 or even 4.2.1 and preserve the baseband if possible.

If some one has a custom one they could message me that would be great.

Let me know the beifits if there are any.

Only reason im asking is because with my T-Mobile Sim in here i occasionally loose signal.

Thanks again

[Poseidon79]

Unless you have SHSH blobs backed up for a particular firmware then you can only restore to 4.2.1 at the moment because that's the only one Apple is signing. You're stuck at 4.0 I'm afraid because there's no way to preserve your baseband and go up to 4.2.1 at the moment I don't think.