Keenser is nowhere near approaching the Jar Jar Annoyance Factor. His presence in the first film seemed only to give Scott someone to talk to for the 6 months (or whatever) they were alone in the facility. We still hardly know anything about him, except that his species may form strong emotional bonds to other individuals, as evidenced by his sadness when Scott and Kirk left. For a small species, they seem adept at climbing objects. Hopefully these traits will be used if they ever give him some important plot-related actions.
It was nice to see Deep Roy still working, I started noticing his name in the early 80s.