Microsoft's new $99 Surface Pen is a steep upgrade from the previous iteration that costs $59 (and which is still available. There are quite a few enhancements that may justify the cost for new Surface Pro owners. But for older Surface devices, the value is not too clear. Here is what owners of previous Surface devices should expect with the all-new Surface Pen.

What's new? The new Surface Pen brings significant changes. Here are the key features being advertised or that we noticed. 1. Pressure levels The new Pen has 4,096 pressure levels, up from 1,024 levels of the previous Pen. The new Surface Pen is simply more sensitive than the last one. While there can be a debate about how significant this advance is, artists and professional inkers prefer more sensitive pens. Higher levels of pressure allow for greater shading or increased detail when drawing. In fact, Wacom's new Intuos Pro Paper Edition tablet features 8,192 levels of pressure – but that device is not a PC, and there is such thing as diminishing returns. For note takers, higher pressure levels make the stylus feel more natural. 2. Decreased latency Latency is the time between when the pen tip hits the display, and digital ink begins to flow. If you draw or write quickly, you will see a visible gap between the pen tip and the digital ink, almost like the ink is trying to catch up to the pen. Real pens have zero latency, which is why they feel natural. The entire digital inking market has been trying to reduce latency to simulate real pens accurately. The new Surface Pen drops latency down to just 21 milliseconds from the previous 40 milliseconds. That is a significant decrease when you consider the display refresh, OS, and apps by default cause 16 milliseconds of latency. 3. Tilt support If you took a real pencil and turned the tip on its side you could use it to "shade." That fanning of the graphite creates a different experience than just writing with the tip. Digital pens should do this. too, but simulating it on a PC is not easy – after all, it's just plastic on glass and the computer does not "know" the difference. The new Surface Pen supports this feature, as well, thanks to advanced hardware. 4. Lower initial activation force Initial activation force (IAF) refers to the amount of pressure needed for a pen to trigger an inking event on the PC – the lower, the better. A similar real-world analogy is how a Sharpie marker can lightly brush against an object and leave a mark versus a pencil. With the new Surface Pen, the IAF is down to around nine grams, making it more sensitive than the last version. Besides the big technical changes with the new Surface Pen, there are subtle physical changes as well. There is no longer a shirt clip, for example, which some people won't like. The single button is also now visually and physically distinct from the magnetic strip. The LED pairing light is also now green instead of white, so there's that (detalil is detail!). Otherwise, the new and old Surface Pens look similar, weigh the same, and take the same single AAAA battery, that should last the same amount of time. What can the new Surface Pen do on older Surface PCs?