I have played a lv 70 warlock, and a phantom summoner of nearly same level. Pet wise I never saw that big a difference (minus the few obvious things).
Once my WC(currently 73 and 67%) makes it to 75 I want to sub another summoner, and I was thinking of trying elven summoner. I was one day in Garden of Eva, in the very center where the dolls and other sick mobs are, and there was a elven summoner with a tank. The tank ran out and aggro'd the entire middle floor, i'm going to say very close to 30 mobs, possibly more. I was thinking "Omg you idiot! you're going to get yourselves and me killed." Then the pet popped off 3 aoe nukes, and they all died. I was overwhelmed. This summoner wasn't extremely higher level or anything either because all the mobs just about dropped adena/mats/etc.
This was back around C4 I believe, so sorta wondering has pet changed any since then?
I will be grouping the summoner with another character/account that I am subbing a buffer on(any suggestions? I was thinking either PP or WC?) or should I go SE to take advantage of EMP for pet?
Personally, I would do SE. Prophet in Second, followed by Warcryer. Warcryer takes too long to max out buffs that max out in B Grade on other buffers... It's like the others were made to be boxxed, and the WC was made to be played actively, Lol. You can "waste" alot of time/XP leveling a WC up for buffs that could be obtained in 2-3 weeks PLing a PP/SE up to level 58 or so.
Summoner already gets a good base of buffs, and SE has all DD buffs that the Summoner doesn't have except Greater Might/Shield. Summoner gets Magic Barrier so that's not much of a factor. You get Resist Aqua, SE has Holy/Wind Resistance. SE has Greater Heals (for you), Purify (for you), Empower (for you). SE DD buffs max out at low level (like Prophet). SE gets VR3 8-10 levels earlier than Warcryer. SE has at least some type of XP rez (like 28% in BW Robes). SE has Recharge if you want to level it up high (degrades after 6 level difference between skill level and your level). SE will offer an additional prophecy in S Grade (should you take it that high) for ES which will not be redundant (PoWind) and offer additional VR comes with that Prophecy (stacks with VR3, like BD VR Song does).
You will do a majority of your XP meleeing mobs (with the summon, or assisting it). WC takes too long to max out buffs that can be maxxed out by 58 or so on an SE or Prophet.
Prophet offers additional buffs, the most important (IMO) being Blessed Body. That can be gotten from a B Grade Staff at level 5 (SOES). Put it on the SE.
I wouldn't make AEing a permanent playstyle unless I had a Prophet in addition to a BD (Dance of Concentration + Acument + Zerk). At 7x I'd take the servitor to HS and get malaria too.