I agree with lots of people saying it gets easier at eighteen months. It is starting to be fun for us all to be together (and out and about) as a family of 5 now (DH, me, DD1-3, DTs 19m), rather than feeling like an assault course or army challenge where you simply have to do or die (for example, changing 30 plus nappies in a day with 3 children under 2 with diarrhoea, getting up so many times in a night that you don't sleep at all, carrying a screaming child up a hill, with another one in a backpack and telling off the third who is also howling etc etc).
The flipside of life being so challenging is that when the challenges melt away you feel so ecstatic. The first time I walked out of the house with a twin holding each hand and my 3 year old holding on of their hands in a line (AND NO BUGGY) was just amazing. We were only walking 30m to our car, but still, even that short trip was so logistically complicated up until now. The first time I went upstairs to get dressed and left them all playing happily together was equally wonderful. On coming downstairs I realised that the older one had been teaching the twins how to remove plug protectors and plug in the hoover, but that's not the point!
And I echo what others have said that seeing them all play together is absolutely heavenly, and you feel that you are getting such a huge reward which you so thoroughly deserve after such a load of hard work. I also feel that their relatively hard start in life, having to settle for less cuddles/attention etc is also being repaid back to them in the form of playmates, social skills and stimulation.
Tonight for example, my DH and I sat and finished our supper (we all eat together at 6ish) whilst the three of them raced off to play a running and cuddling game (basically toddler rugby!) . We had a chat together, there was no one crying or needing changing or arguing or anything broken or tipped over to deal with, so we just enjoyed being together and watching our children for a few minutes. We are only just starting to experience that kind of thing regularly, and it feels so great. It's like we are now in a family which is a great place to be, rather than unpaid labourers in a never ending cycle of chores and jobs that always overlap and renew themselves.