What are the most important factors to consider when comparing different models of affordable electric bikes, specifically in terms of performance, range, and overall value for money, and how do these factors impact the riding experience for commuters and casual cyclists? Are there any key differences in design, technology, or features that can significantly affect the bikes usability and efficiency, and if so, how can these differences be evaluated and prioritized? Additionally, what role do factors such as battery type, motor power, and gearing play in determining an electric bikes overall performance and range, and how can these factors be balanced against considerations such as cost, weight, and maintenance requirements?