How Big is TOO BIG for JSON?

http://josh.zeigler.us/technology/web-development/how-big-is-too-big-for-json/

Records	Download Time*	Chrome (OS X)	Firefox (OS X)	Safari (OS X)	IE9 (Win 7)
1,000,000 (153.37MB)	19:51	DOM Ready:16.4s RAM:1.09GB Loading:browser hang Loaded:usable, 1 tab crash	DOM Ready:14.29s RAM:1.82GB Loading:untestable Loaded:usable	DOM Ready:5.13s RAM: 1.76GB Loading:browser hang Loaded: usable	Data failed to load and browser became unresponsive.
750,000 (115.13MB)	14:54	DOM Ready:12.24s RAM:727.3MB Loading:browser hang Loaded:usable	DOM Ready:13.8s RAM:1.48GB Loading:browser hang Loaded:usable	DOM Ready:3.82s RAM: 1.39GB Loading: barely usable Loaded: usable	Data failed to load and browser became unresponsive.
500,000 (76.69MB)	9:56	DOM Ready:9.13s RAM:512.0MB Loading:browser hang Loaded:usable	DOM Ready:12.19s RAM:1.14G Loading:browser hang Loaded:usable	DOM Ready:2.49s RAM: 1.02GB Loading: usable Loaded: usable	Data failed to load and browser became unresponsive.
250,000 (38.44MB)	4:58	DOM Ready:2.98s RAM:289.8MB Loading:barely usable Loaded:usable	DOM Ready:3.09s RAM:659.3MB Loading:barely usable Loaded:usable	DOM Ready:1.57s RAM: 550.0MB Loading: usable Loaded: usable	DOM Ready:4.88s RAM:537.1MB Loading:browser hang Loaded:usable
100,000 (15.5MB)	2:00	DOM Ready:1.24s RAM:150.4MB Loading:usable Loaded:usable	DOM Ready:1.62s RAM:424.0MB Loading:usable Loaded:usable	DOM Ready:463ms RAM: 296.2MB Loading:untestable Loaded: usable	DOM Ready:1.71s RAM:210.6MB Loading:untestable Loaded:usable
50,000 (7.77MB)	1:00	DOM Ready:521ms RAM:89.7MB Loading:untestable Loaded:usable	DOM Ready:1.08s RAM:308.9MB Loading:untestable Loaded:usable	DOM Ready:243ms RAM: 192.8MB Loading:untestable Loaded: usable	DOM Ready:801ms RAM: 110.1MB Loading:untestable Loaded:usable
25,000 (3.87MB)	00:30	DOM Ready:255ms RAM:67.5MB Loading:untestable Loaded:usable	DOM Ready:646ms RAM:269.3MB Loading:untestable Loaded:usable	DOM Ready:169ms RAM: 130.8MB Loading:untestable Loaded: usable	DOM Ready:408ms RAM: 51.1MB Loading:untestable Loaded:usable
10,000 (1.55MB)	0:12	DOM Ready:144ms RAM:53.1MB Loading:untestable Loaded:usable	DOM Ready:193ms RAM:234.7MB Loading:untestable Loaded:usable	DOM Ready:66ms RAM: 105.1MB Loading:untestable Loaded: usable	DOM Ready:117ms RAM: 35.1MB Loading:untestable Loaded:usable
5,000 (796.57KB)	0:06	DOM Ready:81ms RAM:39.14MB Loading:untestable Loaded:usable	DOM Ready:123ms RAM:220.9MB Loading:untestable Loaded:usable	DOM Ready:42ms RAM: 77.2 Loading:untestable Loaded: usable	DOM Ready:151ms RAM: 18.2MB Loading:untestable Loaded:usable
1,000 (159.59KB)	0:01	68ms RAM:29.1MB Loading:untestable Loaded:usable	76ms RAM:209.2MB Loading:untestable Loaded:usable	41ms RAM: 72.0 Loading:untestable Loaded: usable	63ms RAM: 11.3MB Loading:untestable Loaded:usable
500 (80.01KB)	0:00	DOM Ready:61ms RAM:32.5MB Loading:untestable Loaded:usable	DOM Ready:59ms RAM:209.2MB Loading:untestable Loaded:usable	DOM Ready:32ms RAM: 71.6MB Loading:untestable Loaded: usable	DOM Ready:54ms RAM: 8.6MB Loading:untestable Loaded:usable
250 (40.05KB)	0:00	DOM Ready:55ms RAM:28.7MB Loading:untestable Loaded:usable	DOM Ready:53ms RAM:209.1MB Loading:untestable Loaded:usable	DOM Ready:33ms RAM: 71.4MB Loading:untestable Loaded: usable	DOM Ready:62ms RAM: 7.1MB Loading:untestable Loaded:usable
100 (15.97KB)	0:00	DOM Ready:53ms RAM:28.8MB Loading:untestable Loaded:usable	DOM Ready:66ms RAM:209.1MB Loading:untestable Loaded:usable	DOM Ready:33ms RAM: 70.1MB Loading:untestable Loaded: usable	DOM Ready:39ms RAM: 6.6MB Loading:untestable Loaded:usable
50 (8.05KB)	0:00	DOM Ready:40ms RAM:27.9MB Loading:untestable Loaded:usable	DOM Ready:68ms RAM:209.1MB Loading:untestable Loaded:usable	DOM Ready:36ms RAM: 71.1MB Loading:untestable Loaded: usable	DOM Ready:35ms RAM: 5.7MB Loading:untestable Loaded:usable
25 (4.07KB)	0:00	DOM Ready:12ms RAM:28.6MB Loading:untestable Loaded:usable	DOM Ready:77ms RAM:209.1MB Loading:untestable Loaded:usable	DOM Ready:29ms RAM: 71MB During Load: untestable Loaded: usable	DOM Ready:29ms RAM: 3.5MB Loading:untestable Loaded:usable
1 (192B)	0:00	DOM Ready:7ms RAM:28.2MB Loading:untestable Loaded:usable	DOM Ready:59ms RAM:207MB Loading:untestable Loaded:usable	DOM Ready:35ms RAM: 64.0MB Loading:untestable Lo