A disturbing number of vendors in the customer survey arena (who should know better) promote a one-size-fits-all approach to customer feedback.
Naturally, each vendor claims that its own particular size fits everyone best.
The reality is that different customer feedback programs have different goals, and need to use different questions and methodologies.
For example: if a client is primarily looking to track performance on one or two key metrics, then an automated survey with just a few questions is likely to be sufficient and cost-effective. The disadvantage is that this gives very little feedback at the level of an individual employee--it's very difficult to get a statistically meaningful sample on a single customer service rep--and each survey doesn't have enough detail to be useful at that level.
At the other extreme, if a client is looking to use customer feedback for coaching and training, person-to-person interviews are extremely effective. That conversation with an individual customer has far more impact than months' worth of statistics in terms of changing employee behavior. The downside of this approach is, of course, cost. There are lots of good reasons to use interviews--but if those good reasons don't apply to a given project, there's no point in spending the money.
Another example: Net Promoter is a useful metric for measuring customers' overall level of engagement with a company, but it tells you very little about how good a particular customer experience was. Other factors, such as price, reputation, and earlier interactions all have a strong influence on Net Promoter.
For looking specifically at the customer service experience, Customer Effort is a much more targeted metric. But if you're trying to measure an individual employee's performance, Customer Effort also tends to be too general. Scores will often get dragged down by factors outside the employee's control, such as IVR problems, the wait to speak to someone, or (in a bricks-and-mortar setting) lack of parking.
So to get survey data specific to the employee you need to ask a question specifically about the employee, such as a customer satisfaction question or a resolution question. But those questions often aren't sensitive to important issues outside the employee's control--like price, reputation, or lack of parking.
In the end, then, the only way to make sure a customer feedback process is appropriate to its goals is to tailor it to the particular needs. A one-size-fits-all approach can work in some instances--in particular, the specific goals that vendor's process was designed to meet--but the real world is usually more complicated.