The interesting thing about Bill's House Rules is that they represent OD&D using his own alternate combat system other than using Chainmail or one provided in Volume 1: Men & Magic.
Applying this to Swords & Wizardry, if you combine this with Matt Finch's approach to magic ("An Alternate Approach to High-Level Magic, S&W Complete, p. 50, basically no 7-9th MU, no 6-7th cleric), it is readily apparent that there is little point to going up above 14th level (practically about 10th for martial classes) Beyond, hit points gained are minimal and saving throws no longer improve. For all practical purposes, everyone one has maxed out on their abilities other than the advanced classed in S&W Complete like the monk and ranger.
Character survival would be higher because the most dangerous monsters with special abilities like level draining and swallow whole would have greatly reduced chance to hit.
It wasn't specifically mentioned but I am wondering if OD&D rule of only a single attack is used as well. Multi-attack monsters would have a great advantage in this system. With single attack, the one roll is a synthesis of all attacks i.e a ghoul still attacks with claw/claw/bite but is only single chance to hit and cause 1d6 points of damage (plus only 1 change to cause paralysis in a single round)