I recommend making a list of what is important to you.
The ones you have highlighted (T-Slim and Medtronic) are both tubey pumps so you are probably not interested in a patch pump like OmniPod.
Is size important to you?
Are you expecting to get funding for Dexcom?
Are you interested in looping?
Do you want a tried and tested pump (for another 4 years) or are you willing to be more cutting edge?
There are more things to consider but the answer will be different for everyone of us because we live different lives. But if you work out what is important to you, there are plenty of people who can help you with the features and requirements that are important to you.