According to Cook's Thesaurus,
Quote:
round tip roast = tip roast = sirloin tip roast = tip sirloin roast Notes: This roast is just a cut away from the sirloin, so it's tender enough to be oven roasted or cut up into kabobs. If the roast is trimmed of some fat and muscle, it's called a trimmed tip roast = ball tip roast. Substitutes: tri-tip roast OR rump roast
Meat information sites usually identify this roast as being part of the round in spite of its name. In any case, the usually cooking recommendations are for dry roasting and taking care not to cook it past medium rare or risk toughness because it is very lean. It gets good reviews for flavor.
I think this would be a good candidate for roasting at a very low temperature to maximize the time it spends in temperature range where natural enzymes work their tenderizing magic. A small roast should cook in a reasonable time even if your cook it at 200ยบ. Searing it either before or after roasting will improve flavor.