This is a good feature that increases the safety of the device. Look at how accurate the depth measurement can be. This is very important as many projects that you undertake will require a high degree of accuracy. Routers produce a lot of sawdust. This is a very useful add on that you should consider purchasing.
Some routers offer a variable speed control.
This is not a necessary feature as you will usually want to use full power. However, if the cost differential is minimal, it may be worth considering. Using the router Routers are typically used to cut grooves, hollow out larger areas and create decorative trims along the edge of a piece of wood. The shapes that can be cut by your router are limited only by the number of router bits that you own. The golden rule with routing is to cut a little at a time.