[Nexus 7 Accessories] bftb0:
It depends on what you mean by "finer".

Capacitive touch screens have no pressure sensing, and the precision with which touches are detected is also low. These are separate issues.

Pressure Sensing or Lack Thereof.

Because of the lack of pressure sensing from the screen, there is no way for an app to use the touchscreen alone to modify the pen stroke width (or opacity) during a single stroke (although there are apps that apply changes after a single stroke has been completed, or rely on timing to make the beginning/middle/end of each stroke fatter/thinner/more opaque). Obviously that depends on the application - usually it corresponds to a specific pen effect selection. You can always use the app itself to manually select whatever pen width you want to draw with, in conjunction with zooming to the area of interest, as the previous respondent mentioned. Compared to drawing naturally though, it's a lot of zooming/unzooming and pen selection changes.

I think that the Samsung S-Pen uses either NFC or Bluetooth to communicate pen pressure; but until an Android app publisher integrates BT pens into their app, you are out of luck for pen pressure on the N7. Adonit sells a Bluetooth stylus for iOS; perhaps one day an Android app publisher will integrate with something like that. Note that this is rather an odd scenario though - buying a $100 stylus to use with a $200 tablet.

Positional Accuracy

A fat finger isn't very accurate, but it turns out the touch screen itself isn't very accurate either. If you only use a fat finger, you'll never notice the lack of screen touch resolution. But as soon as you do find a workable stylus with a thin tip, you will notice that you can't do things like normal handwriting at the scale you are used to (using a normal pen/pencil) with any legibility. That's part of the reason you see stylus devices with such fat bodies/tips; it's not necessarily about grip comfort: the smaller the tip is, the lower the capacitance it has, so the screen has a harder time detecting narrow tips. To write legibly in a small text, you have to zoom way in and then write in huge loopy strokes. I've tried a few note-taking apps, and I have come to the conclusion that I can take notes using pencil and paper about 10x faster than using a touchpad. You lose a lot of time constantly panning the screen around/zooming, and even if that were not the case, the fact that you need to make large strokes slows you down. The only advantage a tablet has in this scenario is mark-up of existing documents. (Since you asked about drawing, I'm not sure if this is important to you).

You'll find a lot of Apple fanbois singing the praise of the Adonit Jot stylii - Adonit attacked the problem of "too small a stylus tip" by putting a disc of metal inside a transparent disc that is on the end of a fine metallic tip. The disc can rotate freely on the end of a little "knob" at the end of the stylus. So you can see the end of your stylus with good precision, compared to using a big fat stylus. Kind of spendy though - $15 - $20; maybe that's what makes the Apple cult happy. Sometimes the little plastic disc seems to lose contact with the stylus and your strokes no longer register, or stutter intermittently - it happened with mine within 3 days of buying this stylus. (I've seen suggestions from folks that silver paste be used in the ball joint between the stylus and the disc; perhaps dry graphite lubricant might work too - it needs to be something which is electrically conductive). Also, some people find the clicking noise between the stylus disc and the screen annoying.

Anyhow, food for thought. If you want to save money, buy online (You can find 3 per dollar sets on Amazon). Remember that the only thing that a passive stylus needs to do is:

(a) be somewhat conductive from your hand contact all the way to the tip

(b) be comfortable to grip

(c) not scratch your screen.

Probably that could be satisfied with an item that costs less than 10 cents to manufacture.

cheers