Galaxy Note is getting slower and less responsive I've had my Galaxy Note about 18 months. It's progressively getting slower and slower to respond to user input. Any tap has an unpredictable delay, up to a few seconds. Even typing has a noticeable lag to it. I frequently accidentally tap things twice because there's no response to the first tap.

Is there anything I can do? I'd happily completely wipe and start over at this point. It's at the stage where I barely use it for things like quickly looking up stuff on the net - it's just too tedious.

It's the stock Samsung Android 4.1.2. 350 MB free on the internal storage out of 2GB, 830MB free out of 11GB on the USB storage, and 1.7/14.7GB free on the memory card.

Any suggestions gratefully received.
Such symptoms have often been attributed to the eMMC chip (which is in fact a small SSD that runs a flash translation layer (FTL) software). Android 4.3 added TRIM support to address this.

There exist solutions like LagFix (fstrim) that run on rooted devices and essentially do the same. Cyanogenmod's Wiki has more information on buggy eMMC chips.

However note:
You may want to check your eMMC type first with eMMC Brickbug Check first, to see if you have a known buggy type (where TRIM support is probably faulty).

Some background here, some Samsung eMMC chips are known to cause trouble (they're used in other brands too):
https://plus.google.com/101093310520661581786/posts/2eEd95oN1ZP