Which SSD in E6x20 series?

What is/are the exact model(s) of 256 GB SSD that Dell ships with their E6x20 series?

If price is not an issue, would you rather go with the Dell-supplied SSD, or order the notebook with a HDD and replace it with a potentially better-performing SSD by yourself?

For a E6x20 system, which SSDs with a capacity of 256 GB or 512 GB would you recommend?

 

The latter is usually cheaper and you get an HDD that you can either sell, place in the optical bay with appropriate adapter or put in an external enclosure.

 

But will I also get better performance? For this, it would be important to know which SSDs are provided by Dell as part of their notebooks, and also which aftermarket SSDs are known to be good choices for the Dell Latitudes.

Price is not the primary concern in my case. Also, with an aftermarket SSD, I will lose the Dell warranty. This would be only worth it if an aftermarket SSD gives considerable better performance and/or storage capacity.

I assume that replacing a HDD with an SSD is not more complicated than swapping HDDs in a Dell Latitude (with this I have experience, but not with SSDs). Is that correct?