169% is better
I run a 169% Genoa on a Cal T/2 (27+ foot) all the time until the wind is too strong (about 20 knots). The 150 was put away 15 years ago and the 130 working jib is used up to 30 knots and the 95 storm jib above 30 knots. I do find that on any reach or downwind the sail is great, but when pointing the sail is too powerful and it backluffs the main. There are two cunninghams on the main luff and boom vang to compensate for the backluff and three slab reefs in the main. If the boat has to point really high, I go back to the 130 as it will point about 5 degrees higher. One advantage of the larger foresail is that it will drive the bow down and reduce the plow effect raising the hull speed, but the disadvantage is that the boat will not point as high into the wind.The 169 does lie right along the deck and the visibility is zero except sticking your head around the genoa luff or going forward to see beyond the forestay. I like to keep the boat at between 18 and 25 degrees heel as I tested the sail and found this to be the optimal hull speed for this boat. Above 25 degrees, I down sail to the 130, etc. The gratest advantage is that I do not have to change sails when I shift to downwind or wing and wing. The two sails balance out well for wing and wing and usually a pole is not needed. On longer downwind runs, I will drop the genoa and run a spinnacker(sp?) in winds under 15 knots. The 150 was the original genoa, but I did not trust it as the third time out in this boat, I blew out the stitching on the original main sail. The 150 had the same soft feel so I decided to spend the money and update the sail inventory. 169 is maximum for racing in half ton class. The full batton main, 169 and 130 are Hood raceing sails and they are heavy duty and strong. After 15 years, they have not lost their strengh and are still very hard to bend.Advantages and disadvantages of using larger sails depends muchly on the hull design. Larger does mean more heel and the feeling of going faster (more exciting), but is the hull and rigging designed for that heel and is the mast step strong enough to take the downward force. The deck step for the mast was strenghtened (by original owner) below on this boat as in its early years, the mast crushed the lower support while raceing - too much pressure on the back stay adjuster. The rigging wire is one size above original and the hull is beamy which reduces the flat bottom surface area when heeled(note: fin keel) and deep rudder. If you really want to know the true advantage or disadvantage of the larger sail, test the hull speed with the two sails with a knot meter or GPS in the same wind and then measure the pointing ability of the two sails. Check for off course drift as I am sure you will find the genoa has more drift and then run the sail that is appropriate for the wind conditions and desired course.