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The physics are simple to explain, but opinions are all over the place. It all comes down to what you believe the most.
Theoretically, a sloop boat is faster then a uni allround, that is when considering everything else equal. However, most boat also differ from eachother in several important aspects and that makes comparisons problematic.
Physics,
A sloop rig can always fly MORE sailarea then a uni-rig. On anything but an upwind leg where angle of attack is important the boat with more sail area wins (assuming equal aspect ratio's, luff length and tipheight). Fitting a spinnaker to boat versions reduces this performance gap. Making the sloop boat clearly favoured on a reach and leaving the conclusion still open on the upwind. Downwind is pretty equal now.
On the upwind leg the balans may turn either way or hang flat depending on the details of the design. Sloops point lower but get more drive low in the rig and are easier to not stall, an inexperienced crew can get more performance out of a sloop then a uni. More drive means more speed and if that speed compensates for the lower sailing angle then both boats have equal vmg which is what makes you reach topmark first. F16's are counting on that particular aspect to a large extent. However it does assume that both rigs have rerceived sufficient or equal amount of development. It is probable that sloops have reached alot more development over the years them uni and lots of sailors are soloing their sloop rigs which is some drawback on performance.
The jib is not a hinderance on the upwind leg as many will claim. It does smooth out the flow over the main and will have it producing drive more consistantly , especially when the rig is moving about in waves or when the wind fluctuates. Also, the jib can operate well as surprising low angles of attack because of the interaction with the main. In affect the jib is in the updraft zone of the mainsail and does not nearly need as much AoA as a single sail does. the hit on pointing ability is therefore rather limited. A unirig needs an apparant windangle of about 20+ degrees where a sloop rig needs about 26+ degrees. Assuming as sloop sails at 45 degrees to the wind and a uni at 39 degrees then the uni rig gets 10% more saildrive. 20% additional sailarea will speed the sloop up sufficiently to equalize vmg , 15 sq.mtr times 20% = 3 sq.mtr where the F16 jib is 3.7 sq.mtr.
Do you understand the balancing act now ?
Ofc ourse other smaller factors are also at play like righting moment etc but I leave these out of the discussion for now.
Righting moment is however important and that is in my opinion the largest factor in creating difference performance between sloop and uni f16's (text above refers only to sloop en uni boats in general with all else equal).
Basically I banked on the uni being faster downwind then the sloops here becaus of lightweight and ability to fly sooner and sail deeper. With an optimized uni sail the loss on the upwind will be limited and subtracting these from one another will go a long way to equalize both F16's but of course never fully. In sub trapeze conditions I expect the uni to be slightly faster and in big wind to be slightly slower, in the medium stuff it is a fine balancingact.
That is the theory and consult Marchaj, Bethwaite, Ganty and other books for the details.
First point of call for any solo sailor is however to buy a dedicated uni sail for his F16 if he wants to race often that way. It needs to be latter all over and fuller in the part where he jib flies. It may also have a leech that opens more easily to spill air (at a lower righting moment level). All things a sloop main will not have. This alone will go a significant way in getting max F16 solo performance. The rest is learning how to sail it properly since their is no jib to help you trim the main or point.
