I have a similar grinder which I use for plane irons and my joinery chisels. i.e. they are great for flat bevels. Yes you could use it to create a long grind but you would still need to control the profile by your method of moving the tool during sharpening. That is what causes the most difficulty for users and why they use jigs. or in my terms, guides. In my terminology a jig forces you to follow a set profile, a guide assists you. All of the so called grinding jigs I have come across, should be called 'guides' as they require the tool to be moved in the 'right' way to achieve the required grind. If you leave the tool in one position, you still remove metal and end up with a 'flat' on your profile.
This looks a good buy, but what are the costs for replacement wheels? They all need replacing at some time.
I may be biased but I have used a 6" basic bench grinder for all my woodturning sharpening, for many years. The grinder cost £35 (yes, a few years ago), replacement 'pink' wheels are around £20 and the Trugrind jig cost me around £90. Allows me to sharpen all my tools, with various grinds, easily and repetitively.