When most people are taking a look at gas logs for purchase, they mainly consider

whether the logs are vented or vent-free and the
way that the logs actually look. There are many more considerations that you must take into consideration that some folks may not even know exist. There are many new additions to the traditional gas log set that should be considered.
Remote Control
Many folks appreciate gas log sets that can be controlled by a remote control. Remote controls for gas log sets can be used to turn the logs on and off, change the temperature of the logs, and turn on the blower as well. A remote control makes gas logs even more convenient than they already are and whether the gas logs come with one should be factored into your decision. Often these are an optional feature which comes with an additional cost to the base price of the appliance.

Safety Pilot Light
Most reputable gas log dealers only sell gas log sets that come with safety pilot lights, and a local building inspector won’t approve the construction of your gas log set without one. Safety pilots do not allow gas to flow to the appliance unless the appliance is turned on. By preventing gas from flowing when the appliance is not lit, you will prevent natural gas from sitting in your home, which is a safety hazard.
Carbon Monoxide Detector
Some gas log sets come with a carbon monoxide detector but some do not. If the model you are looking to purchase does not come with a carbon monoxide detector, you will need to purchase one for your home, as CO is a safety hazard with or without gas logs in the home.
Oxygen Depletion Sensor
Most gas log sets, especially vent-free gas log sets, come with an oxygen depletion sensor which will automatically shut off the appliance and alert you if the level of oxygen in the room drops too low. This is definitely not an amenity in my opinion, more of a necessity if you are looking to install vent-free gas logs and is great to have if you have a vented gas log set as well.
Service and Installation of Logs
Unless you are a licensed professional you are going to need to not only have your logs installed by a professional, but have them serviced and the chimney inspected yearly. Whoever you purchase your logs from should be able to install them for you. Be wary of purchasing from deep discounters or from home improvement stores if they are not able to install them for you or instruct you on how to contact someone who is capable of installing that particular make and model of gas log. Long term servicing for the logs is also required, so be sure that you are purchasing from a company who you are willing to work with. Many chimney sweep companies are licensed to service gas logs as well.