I just bought a case of Redline SI-1 that I'll be using at ~5oz/fillup, less if not a full fillup (I'll log fuel added vs Redline added to keep tabs on how much Redline is in the tank each time.) To measure, I bought a 5.25 oz bottle of Gumout HM (Regane) that I'll use first. This should be easier than trying to pour 1/3 or less of the 15 oz Redline bottle in at each fillup.
As far as feeling the UCL or cleaning, I never have, even with older vehicles. I always fillup at Mobil, Shell or Sunoco stations, so maybe that's all that's needed to keep the system clean. I'll decide after using up a full case, and then a few fillups with out additive, whether there's any gain to be had.
However, Redline touts that it precludes the need for octane boosters (or something like that; maybe as a result of cleaning, and not any inherent octane-boosting properties it possesses,) which when combined with it's great cleaning ability, slight UCL properties (from what I've read - it doesn't claim to be an UCL, IIRC,) and reasonable price, I might stick with it for that all-too-valuable peace of mind factor