While It's pretty obvious with that + 1 to paladin skills, that this armor is obviously designed for this character class, I'm actually having doubts of real usefulness of this armor. Sure max resist are nice, and it's the only armor that gives a bonus to Chance to block and those skills are icing on the cake but aside from the resist, there simply isn't anything interesting enough for me to take it. Ever since I've got the HoZ (damn that thing seems quite overpowered when in comparison with other class specific items especially when given a fact that it's a shield) I have staple resists around 50 and when things get rough, I simply put on Salvation, until I reach Gloams, Vampires, or other pesky snipers. OK I can see the point that I can have 90 resist with Salvation on. That's pretty good however imo Paladin should much more care about physical damage reduction. Therefore I'm hesitating about giving Shaftstop away for GA. I don't think about replacing HoZ with SS. And with that in mind there is not much left, maybe the helm slot but I don't have CoA or 2 bers, I do have Vamp Gaze but I still like my Guillame's Face too much to give it away for it. All in all it just doesn't seem that GA is worth all this trouble. But it might turn out that it's the best choice. What do you think about that?
Guardian Angel, while having some nice Paladin-suited mods, is not one of my main choices for a char's main armor. Paladins should not really worry too much about resists in general, as items like HoZ, CoA and Um runes in sockets should take care of it.
The main use that I have found for GA is on a Merc for Single Player Baaling. I have a lvl 98 Sorc in SP that has her Merc wearing an Upped Eth, Um'd GA over a Fortitude for the simple reason that Achmel & Co poison Dmg is such a Merc Killer.
For your paladin there are far better choices, depending on the build that you are playing. For Melee builds, if you are on a budget, try a Duress. It has solid mods all around and is a great armor. Shaftstop is not bad either but will slower your run/walk speed and it lacks resists. The tried and true Skin of the Vipermagi is good for casters as well decent for melee chars. Top of the range for melee would include, in order, Fortitude and then CoH. Enigma if you have access to Ubers. Casters are well served by Skin, CoH or Enigma.