Downside to upgrade iPhone 3Gs 3.0.1 on 04.26.08 to 3.1.2?

[cashonly]

What is the downside to upgrade my iPhone 3Gs 3.0.1 running 04.26.08 to v3.1.2?

I'm on AT&T and am not planning on leaving for a couple of years (got the phone just over a month ago), so unlocking is not an issue.

What is important to me is:
Being able to use MyWi for a hotspot
Being able to turn my phone off and not lose my jailbreak

There are a number of apps requiring 3.1 that I want as well as MMS and being able to arrange apps thru itunes. And these all require 3.1.2

So, is there a downside?

And what is the best way to do it?
Just use iTunes and do the firmware upgrade Apple provides, then use blackra1n RC3?
Or is there a better way?

[iPhone-power]

What is the downside to upgrade my iPhone 3Gs 3.0.1 running 04.26.08 to v3.1.2?

I'm on AT&T and am not planning on leaving for a couple of years (got the phone just over a month ago), so unlocking is not an issue.

What is important to me is:
Being able to use MyWi for a hotspot
Being able to turn my phone off and not lose my jailbreak

There are a number of apps requiring 3.1 that I want as well as MMS and being able to arrange apps thru itunes. And these all require 3.1.2

So, is there a downside?

And what is the best way to do it?
Just use iTunes and do the firmware upgrade Apple provides, then use blackra1n RC3?
Or is there a better way?

Blackra1n is causing some connection, Wifi and MMS problems.

I recommend using Pwnage Tool 3.1.4 (Mac only) or getting a custom restore IPSW from Internet and using iTunes to install it. You will have a solid jailbreak but no need to unlock.

Go to iClarified for a tutorial.