It's subjective though, really.
The positives in my relationship/things I'd miss:
Being another adult around to help out with DS, meaning I have more freedom to go out (even just to the shop, but properly out too if we ever had the money), someone to support through the difficult bits, pick up the reins if I'm having a bad day, discuss stuff with etc etc. (Bad side - having to discuss stuff when it would be easier to just make the decision by myself)
...erm... the sex is nice 
Someone to share the housework, the cooking, the bringing in of money, and the worrying about and organisation of the above. Currently if we did not have his wage I would not be able to continue my university course this year.
He has a car so drives us to places, gets shopping in car, etc. (I can't drive - want to learn when we have more money)
He introduces me to new things. We have fun together. I like his friends and family.
(Sorry, I'm massively tired and started this off feeling all fuzzy but ended up not really knowing what else to say, so just the practical sides really.)