How much noticable difference is there when using the two servos for control surfaces. I have several 3003's. The only difference in the two is the second ball bearing. For most sport flying and a little ocasional 3d manuvers, would these be ok to use. Or would upgrading them to the 3004 make a big difference?

From what I understand, the only difference between teh two, is that teh top bearing is metal balls in the 3004, and a plastic sleeve (bushing) in the 3003. I also understand that the 3004 is now replacing all the 3003 in teh standard flight packs and Tx packages; becomming 'the standard'. (Which replaced all teh 148s at one point...)

Personally, I don't really see / feel a difference, other than the 'Oooh bearings' factor. One is as good as another.

Use them where-ever you wish, just make sure they're balanced ( use two 3004s - one in each wing... instead of one 3003 and one 3004. Just in case there is an actual difference.. but doubtful)

It would make for an odd flight to have one dragging a little slower than the other. I did see where a person can order an upgrade kit, just a bearing with a new servo top that says "3004" Its like about 13.00 but that is bearings and tops for 4 servos, the cost of just a single new 3004 servo.

I've been using nylon bushed servos for years and years in .40-sized and smaller sport planes, and I still use them, and they work just fine. Though with BB servos coming down in price so much, I now have a mix of types. You really have to be pushing things for you to start to notice the difference, and I frequently forget what is where. I do agree that you should match servos on things like duel aileron servos, but I mix and match in planes all the time, like having 4 differnet brands of servos in the same plane. (Had a JR, Hitec, GWS, and Hobico). (only downside is that it makes keeping spare parts straight a royal PITA. Why can't they all use the the same @#$@ spline diameter and tooth pitch?!?)

The cost difference in the 3003 vs the 3004... may as well get the 3004. (its only a couple dollars a servo...)

The ball bearing gives less play at the output shaft. A very good thing for Flutter prevention. If that were the only difference it is worth the extra cost. But the ball bearing also has just a bit less friction... so the servo travels just a bit faster and gives JUST A LITTLE crisper response. (you gotta be really good to see the difference in flight...)

Match the servos used for ailerons if using 2 servos. and as you get replacement servos... go with the 3003 over the 3004.

I already have six or seven 3003's. I also found a couple Futaba SX 100's in my box. I think those came out of a car, but at most I would only use those for throttle servos. I think I will just use those if there is no slack in the output spline, from the bushing being worn out. Later I will just get all digital servos at one time.