How do the costs and benefits of renting versus buying a concrete grinder in Los Angeles compare, and what factors should be considered when making this decision? What are the typical rental rates for concrete grinders in Los Angeles, and what types of rental terms and agreements are available? How can a customer in Los Angeles ensure that they are getting a high-quality and well-maintained rental concrete grinder, and what types of accessories and tooling are typically included with a rental concrete grinder Los Angeles? What are some common mistakes or issues to avoid when renting or using a concrete grinder on a project in Los Angeles, and how can a customer ensure that they are following all safety and usage guidelines? What are some of the most reputable and reliable rental companies in Los Angeles for concrete grinders, and what types of customer support and assistance do they provide?