Ramping is cool, you get to handle increasingly heavier weights! It's really fun.
My personal issue with ramping, is that at some point, (I don't know, 4-6 weeks in) I stop "ramping" and just start picking weights, which are more like strategic warm ups, that will allow me to get a new 5 rep max on that top set. After awhile, this cuts out a lot of the useful volume from the 1st four sets, and has me doing top sets that are too heavy.
Also, once you get over three plates, you have to start adding more sets. 6x5, 7x5, it can get to be a mess.
Sets across is useful. You do a bunch of clean, strong reps with a moderate weight. You get 5 "first reps" to practice your technique. Great advice (stolen from Reed) is to use about 65%. My problem with the sets across was that after awhile, adding 10 pounds here and there, the weights end up kind of heavy, and the last reps of the last sets start to get sloppy. Then the whole thing turns into a grind.
Years ago, I tried to ramp to a top set of 5 on Monday, then do 5x5 with 80% of that weight on Wednesday and 5x5 with 90% on Friday. This worked great for about 3 weeks, then it wore me down pretty fast.
Last month, I tried out Wendler's 5's Progression. You do 3 ramped sets of 5, then some back off sets of 5. The heavy weights are waved week to week, and the back offs are based on that progression. The whole set up gives you the benefits of ramping, and sets across. It also gives you a frame work to progress the weights, without grinding yourself away. All the guess work is gone. It's really great. I totally recommend checking it out. Even if you don't want to use Wendler's whole program, his 5's progression could work for big lifts in any routine.