Pros
Gartner hiring process brings in only very talented people, so there are no weak links on your team (practice domain). Teamwork and comradery amongst Peers is very high. World-class brand recognition.
Cons
In the Partner position you are assigned a portfolio of clients. Gartner business model is you are responsible for your portfolio and guaranteeing its renewal, (regardless that the Account team (sales) owns the contract negotiations and writes the proposals). Bankruptcy, COVID, Mergers & Acquisitions, resignations that leave you with an open seat, if your portfolio happens to heavy in an industry with a down turn (e.g. Energy), and anything else outside of your control, is not taken into account for non-renewal. Stellar client reviews and positive internal Gartner staff ratings will not save you from being put on a Performance Plan and then let go. Revenue is king and client satisfaction is not a key consideration for your performance review.