The Deva is a neutral good medium outsider, while the Angel is an unaligned (angels in 4E serve all gods, including evil ones) medium immortal.
The Deva has an initiative of +8 and a godly perception of +26. You won't be hiding around them. By comparison, the Angel has an initiative of +12 and a perception of +11.
The Deva has an AC 0f 29 and 172 HP, while the Angel has an AC of 30 and 141 HP (~80%).
The Deva's saves are +16, +13, +11, while the Angel's Defenses are 26, 24, 25 (+16, +14, +15), still fairly in line. The Deva also has a +4 bonus against poison and evil, damage resistance 10/evil, resistance to electricity and fire 10 and is immune to acid, cold and petrification. The Angel on the other hand has a meager resistance 10 to radiant (holy damage) and is immune to fear. For as long as it's not bloodied, all attacks against it also gain a -2 penalty and 5 squares around it are considered difficult terrain for enemies.
The Deva flies with a speed of 20 squares and walks with a speed of 10 squares, which is ridiculously fast compared to the angels 6 walk and 8 hover speeds.
Moving on to offense, the Deva attacks with +26/+21/+16 and deals 1d8+14 dmg. If it hits the same creature twice in a turn, that creature must make a DC 25 save or be stunned. It also has a number of spells, out of which I'll mention Blade Barrier and Heal as dailies and Holy Aura, Holy Smite and Holy Word at will. The Angel has one +19 attack, which deals 2d10+11 radiant damage. Going purely by those numbers the Deva will deal ~25 dmg/round, while the angel will deal ~11/round. It is an angel of protection, which means that it also gets a power where it designates an ally which gets +2 AC and half of the damage dealt to it is dealt to the angel.
So again, looking at the conversion guidelines:
- -10 to Defenses to get saves still holds
-the MV monster has ~80% HP of the PF monster
-the MV monster has less protection, defenses and powers overall
-the MV monster has a considerably lower attack (the average is roughly the same, but the Deva's highest attack is 7 points higher)
-the MV monster heals about half the damage of the PF monster per round on average
I'll do one more epic creature next and then I'll try to extract some more solid guidelines.