Both of this modules are still work in progress but you can make good use of them. Currently Glossify is my favourite because it links to taxonomy terms when needed. Link inteligence has maybe a bit better perspective and whole architetture behind SEO Tools module looks very promising but when you use it you won't be satisfied so much with results and links it makes, although there is high level of customization present and also bulk generating of links.
Glossify misses bulk generation of older nodes(nodes made before glossify install) but saving node again and/or unpublishing then publishing them will make them "glossify". Just bare in mind that you have to do this also for source and target nodes. If you have both sources and target KW in both you will have to do this twice so each node can be glossified and reglossified so maybe best method would be to just use VBO and to this twice on all of your older nodes (try using SAVE node command once to achieve this).
In the end if you want full control and don't trust machines to make your links you can just use Alink module where you make manual list of key words and links. All 3 modules don't work with more than one language. There is an option for language barrier in glossify , but its often breaking down and links are just wrongly matched, since you don't have any way of changing them manually other then going into Database.