I have had the lyman and the Hawkeye.
The lyman is a digital image, still plenty good enough to examine a bore for carbon for cleaning. The lyman also has the ability to take pictures, and you just plug the chip into your computer. By using this option, you can monitor your barrels steady degradation from new throat to shot out throat.
The hawkeye is a true optical image, and the contrast is brilliant. The down side to the Hawkeye is saving pictures, as that unit is an additional cost of $1200 over the cost of the Hawkeye....YIKES!!!
The first bore scopes I used were endoscopes, and there was no 90* eye piece. So, when you are looking down the barrel, you were looking down a straw. I am not aware that there is a 90* eye piece for the endoscope. You can use the endoscope to see the fouling in the barrel, and for that purpose, it worked great.
OK, for a gunsmith, the Hawkeye is a needed tool. For a shooter wanting to examine his bore for cleanliness, the Lyman will cover this chore in spades...$200. I wish that everyone reading this post could order a lyman that is not a gunsmith in the next 5 minutes....I am not affiliated with Lyman or Hawkeye.
There is More Bull S. on the net concerning cleaning guns than you could ever imagine.