OME is the way to go if you want function over looks (offroading vs physical appearance of a lifted truck).
OME coils come in a few choices of spring rates to select what suits your needs. My OME is so close to having spacers, it's hard to tell on-road the difference.
OME does tend to make the truck corner more level on-road. Offroad it plants the truck much better over rough surfaces. It is then that you really notice the difference (improvement) of the OME over XREAS equiped stock suspension.
I had Daystar spacers (2.5" lift) and did lots of offroading setup like this. Its downfall was it could not carry camping gear etc very well. The load would overcome the stock coils.
There is a lot already written. Search thru it all and make a decision based on what you think you might want to be doing in six months time with your truck.
Try to project forward, thinking about things like roof top baskets, tire and wheel upgrades, bullbars, winches, lights, offroading opportunities, expected payload....
Personally, if I was just going to do a little light offroading a few times a year, spacers are great. However, for not very much more ($) you can have OME.