Capacity or volume is not a "keeping up with Joneses (or enemates)" type of thing for me. I like different volumes, solutions or retention times depending on my mood and what I feel like at the time. For years I took only 2-2.5 Q but then wanted to experiment with more, so recently have become accustomed to 2.5 as a minimum depending on solution, and now routinely do 2.5-3.5 Quarts. A few weeks ago, I had more time and interest, so I used a very benign soothing enema of just saline and took 4 quarts, held it for about 10 minutes, enjoyed the distention, and expelled it.
Very interesting and pleasant, no cramps or sequelae. I rather marveled at the time that I could hold that much, but there was absolutely no cramping, pain or other indication of problems, so I had a nice time. I'm very sensitive to cramping and pain during an enema, so it's pretty easy to keep it safe. The next day, I intended to repeat it, because I had such interesting sensations, not because I felt in any way like "well, I took as much as he/she did." I started the enema, and after taking my whole 2.5 quart bag as I did the prior day, I got up to refill. I frequently indulge my submissive side and run a very pleasant fantasy of my partner dominantly giving this to me as part of her requirements for the day. I refilled the bag, started again and reached the 4 quart mark as before.
I held it for a little while, really enjoying the newish sensations and playing with my fantasy Domme, and it felt so good I just opened the bag to see what it would feel like. I still had no problems and enjoyed some masturbation and the fantasy voice of my partner. By the time I looked up again, the bag was empty, so I had sort of semi-intentionally given myself 5 quarts. I held that for a short time and then found the trip to the throne especially interesting and had a long but pleasing release. I think I'll keep it to 4 max from now on, as I enjoyed both but didn't feel like the extra quart was really worth it for additional enjoyment, filling and draining time. My enemas are for enjoyment and sexual stimulation and for mutual pleasure with my partner, and 4 quarts or less delightfully satisfies my/our pleasure quotient.