Sorry, I disagree. The strength of a commitment does not relate to whether you're going to get married or not. Divorce statistics proves me right on this.
Enthusiastically agree. i've been with my SO four over 4 years. He in med school while i worked, and now me in law school while he in residency. We have learned (through trial and error) the realities in a seriously committed relationship - as a couple and as motivated, intelligent individuals. One thing we've learned throughout this process is that for us - for people who both have real, professional and personal - goals, is that you cannot predict what the other will do or be faced with in regards to their career. Future plans as a couple takes immense planning and coordination/some may say sacrifice. Getting married at the get-go without realistic understanding of futures 1, 5, or 10 years down the road will not end well...
I have many family members who married while one was in school and the other working...seemingly with the idea that marriage would bridge the gap in their seperate lives. Now, with children and seperate careers/lifestyles, they are divorced. Unfortunately, with children. Where is the benefit in that?
Size of ring, or at what point you are in your relationship with your SO, does not ameliorate the decisions yet to be made unless serious consideration towards both professional interests are identified and worked through. This is hard.