Dungeon spawners are way too slow for my tastes. If I don't have a double blaze spawner or enderman farm for XP, I'll get it from smelting things. Food, charcoal, stone bricks, and even kelp can out-pace a single skeleton spawner by a wide margin if you're actively farming them.
Another very effective way to get XP is by mining Nether quartz; I can mine around 1,000 ore per hour which comes out to 3,500 XP per hour, or 11-12 level 30 enchantments (or about 4 in 1.6.4; I actually mostly enchant books at level 22, where there is a good chance of many of the enchantments that I use, and otherwise a slightly lower chance is more than offset by being able to make nearly twice as many enchantments). This also provides me with something to build my main base with other than stone; while it is not renewable I have no need for extra XP after I've made all of my "caving gear", as I gain over 5,000 XP per play session as a by product of caving for fun, thus I've never made an XP farm.
I mean they are like carrots but much more useless i just accept them as ultra downgraded version of meat. its just food
You need to cook potatoes to make them worth eating; a raw potato only restores 1 hunger and 0.6 saturation while a baked potato restores 5/6, making them nearly 7 times better overall (prior to 1.8 they restored 6/7.2, the same as cooked chicken and over 8 times better than raw potatoes).
Also, I find them far more convenient than steak due to the fact that you can eat 2-3 at a time instead of 1-2; as mentioned before, I often only eat once my hunger has dropped down low enough to eat without overfilling myself and with steak I find myself eating a lot more often or wasting food (one steak eaten at 5-6 hunger bars left restores 8 hunger and 12.8 saturation (20.8 total) and two eaten at 4 hunger bars left restores 16 hunger and 20 saturation (36 total), with 5.6 saturation being lost, compared to 12 hunger and 14.4 saturation (26.4 total) for 2 baked potatoes eaten from 3-4 hunger bars left, with the option to eat 1 (6/7.2, 13.2 total) with 6-7 hunger bars or 3 (18/20, 38 total) with 1 hunger bar left; this last case wastes 1.6 saturation unless I first eat one then eat the other two a while later, as I often do. Normally, I only eat when I'd waste food if I get poisoned or take a lot of damage). The need to eat more pieces of food is offset by the need to eat less often.