Factory reset to restore performance? What are the disadvantages? tl;dr: What bad things will happen if I do a factory reset?



So I've had this original Droid for about a year and a half. I love this phone, and if only I could get it to be a bit faster and have a little more internal memory I'd keep it forever. However, it had been around for quite a while before I jumped on the Android bandwagon and it's getting pretty creaky in the joints. Further, my contract isn't up until next April.

Over that time I have installed and uninstalled a lot of applications (often to answer questions here or, more likely, from recommendations here). I have tried no fewer than five different home screen launcher apps.

I have streamlined the apps I'm using and moved everything possible to the SD card. Still, performance just isn't that good. I don't want to root (although I've considered it), but I need this thing to carry me for eight more months.

Could a factory reset possibly help? What is the downside to doing a factory reset?

I'm not concerned with losing anything important. Between the Market and AppBrain I have no fear that I won't be able to get key apps back. I also have all of my important data syncing to the cloud so I've no worries there.

Is there anything lost that I can't recover myself? For instance, am I going to have to go back to the Verizon store and have them reprogram my phone number? Is there any reason I shouldn't just go ahead and to the reset?



Update: So I took the plunge yesterday and everything worked out fine. I use Google 2-factor authentication, and that complicated things a little bit. Once I got past that it has been fine. I have quickly the discovered the apps I really need, and have been enjoying much "snappier" performance.

I'm just sorry that I can't accept multiple answers. These have all been very helpful.
You'll be in the clear for the most part.  I factory reset my Moto DROID v1 a few months back, and while it is a little scary to do a total wipe like that, you really have very little to lose.  Like you say, you'll be able to redownload any app that you have previously purchased, and your contacts / e-mail should sync back up just fine.  It is a little frightening to see the commissioning screen on first boot, but you'll get past that quickly.  Like you, I had tried clearing out as much as I could and getting "lean", but I still saw a big performance boost after resetting.

One thing you will want to be certain to do is save any text or MMS messages that you have received to your SD card.  These get stored in system memory by default and will be erased if you don't save them to the SD card first.  You can save an image attached to a text by long pressing the image.  You'll get a pop-up with the option to save it to your SD card.