You can type in Lucas Top End into the search engine and see this topic has been covered. Not railing you for bringing it up, but if you pre-search the topic you will get an idea of how people are going to answer your question. You'll get some pros and cons for responses.
I use Lucas Injector Cleaner/Fuel Conditioner in the following engines I own:
1999 Legacy GT
2008 Ninja 650R (racer)
1988 Hawk GT
1996 Honda Harmony Lawnmower
2011 Troybilt edge trimmer
???? Homelite chain saw
The cars and bikes get the recommended ratio every 3 tanks.
The mower, trimmer, and saw every fill up (cause I premix a 5gal can)
The mower, Ninja, KLR, CRFR have all had the heads off and I've seen no evidence of why I should not use it. I have no scientific method to claim it pays for itself, but I've been a part time motorsport and small engine tech for almost 20yrs now and have used Lucas and similar products to agressively clean top ends with positive results. I'm not the only one.
This is not a specific promotion of Lucas that I'm giving. It does seem to be the flavor of choice lately. Use any top end cleaner that grabs your fancy.
I currently like Lucas because I have gotten unsolicited endorsement for it from other techs in the automotive field as well as motorsports, and to me equally as important, Lucas promotes and supports motorsports.