It's more effort than it should be to control the analog sticks on a bare vita, especially for slight adjustments. Grip accessories for the whole vita help as they reposition your hand and give you a more relaxed grip on them but the material on the top is still too smooth. My thumb slips. And they're small.
The grips fix all of that and for not much at all (unless you end up having to import them). They're so useful (and they can come off with a lot of friction, sliding against like a tight case) that I decided to order more (from this UK eBay seller - don't forget best offer option, especially if buying more than one).
This is the item package but I'm sure they sell the same ones everywhere so it probably varies.
They make it just so much more relaxed to move and and control the nubs, especially slightly adjustments. For games that depend heavily on them, and just generally to have on at all times, they're great.
Amazon have them from Bluecell but I've heard mixed things about them...Others sell them with mis-matching pairs or a bundle of 6 not 8 - missing the spiked ones, which are great:
I haven't tried them all as they're a bit of effort for me to put on and I like these ones.
I know a lot of you like to keep the profile slim for the Vita - these don't add much at all and from normal viewing distance it just looks like the vita comes like this.
In the photos I set it up so the spikes show up and are most in focus but they blend very well.
The case is the Hori Vita Grip Case and it's great other than than being big. The sliding is loose but I'm going to try and improve it. Non-slide mode feels great, only thing is you can't reach rear touchpad as easily that way.