There has been a fair amount of discussion in regards to two row and three row radiators and if the three row provides better cooling.
A three row has more metal in the core and so some say the air flow through it is reduced. This reduced air flow then provides decreased cooling performance.
Some with the three row say they work just fine.....and I won't argue that fact assuming they live in a climate where they are not pushing the envelope of the cooling system during the hot summer months.
Others say that in order to reap the benefits of what the three row offers, you need to replace the stock fan clutch and fan with the heavy duty fan clutch and a 7 blade fan. This provides for more air flow and brings the cooling performance back.
A friend of mine, who lives in Tucson, AZ (which also gets quite hot in the summer) installed a 3 row and had poor cooling performance (he did not install the HD clutch and new fan). He removed the 3 row and installed a two row.....leaving everything else as it was. No cooling issues from that point on.
A good aluminum radiator runs about $500 (sometimes more) and often times requires you to do a little fab work to get it mounted properly (not always....depends on the manufacturer). A friend of mine has one and has reported no improvement in his cooling performance.
I have a two row all metal replacement radiator in my TJ and it seems to do as well as the factory unit that it replaced.