The most accurate maps on both Lakemaster and Navionics chips will be the “survey lakes”. Both companies highlight the survey lakes on their lake lists. The survey lakes on both lakemaster and navionics chips are excellent. For LOTW, both companies now offer a LOTW chip that is highly detailed and accuarate. Check the lake list for your lake.
Non-survey lakes will vary in accuracy and detail. Consider them bonus lakes, IMO. Some are quite good, while others are off quite a bit and lack the detail we all want.
Lakemaster lake lists
Navionics lake lists
The above links offer short cuts to the most popular map chips.