The lift bowl design is more ridged than the tilt head; this allows for a stronger motor and in the case of the Pro 600 and 5+ the use of the spiral dough hook.
You only spill batter taking out the bowl if you try to take it out with the beater, whip or hook still in place. If you release the attachment first, you can take out the bowl out with only a slight tilt back and nothing spills. If you lift the head on the tilt head mixer so you can spin off the stuff on the beater, you are asking to get hurt. You could of course do this on the lift bowl mixer by lowering the bowl part way with one hand and controlling the motor with the other, but again, I don't recommend that.
Either style of mixer does a very good job. I think that long term, the bowl lift is better than the tilt head. I have both; I use the lift bowl more.
This tends to be kind of it depends on the person using the mixer. My mom and SIL have the 4.5 tilt and like it. It is smaller and slides under most upper cabinets. It is lighter if you have to lift it. I feel like I am using a baby toy when I use them. I have had the 5 qt version for 20 years and it performed perfectly until my husband put 7+ (who knows how much he won't measure) cups of whole grain flour in it and killed it. I have been telling him 5 cups no more for years. He expects kitchen toys to work like his tools in the garage. I am hoping the 6qt professional version will deal with users unable to deal with limitations better than mine which had fiber gears designed to fail and protect the motor from burning up.(this is what the KitchenAid repair guy told me 18 years ago when I did the same thing to it). It looks like from all the negatives that there was a bad run of mixers put out in 2005 - 2007, I hope that the new one suposedly "all metal" "professional overload reset" does better.
Otherwise I guess we will have to put the beater in the drill press and make bread.
I am a fan of the bowl lift and I personally prefer this option over the tilt. I like being able to drop the bowl down for scraping the sides while mixing or adding ingredients and I like the fact that the beaters are not lifted up at an angle in the air with all the wet ingredients; there is more potential for flinging dough out of the bowl and I just think it is more awkward period.
There are advantages and disadvantages to both types of mixers Tilt head (TH) and Bowl lift (BL) TH Mixers 1) TH mixers have a physical limitation due to their inherent design, which places stress upon the tilt mechanism. They are therefore limited to under 1/2 hp and less than 5 quarts maximum bowl capacity.
2) TH mixers are the easiest to operate physically and ergonomically as the tilt mechanism allows for the attachment to be completely lifted out of the mixed ingredients. Attachments and bowls therefore, can be easily interchanged as necessary with much less mess and fuss. Further the TH machines handle under 5qts total volume, which equates to less weight.
3) Due to power and stress limitations, TH mixers are not the best design for kneading large batches of thick bread dough. Further, TH mixers are not available in commercial versions.
BL Mixers 1) BL mixers (counter stand) were initially designed for commercial use. Since they don't have a tilt mechanism, they can absorb greater stresses. They are available in 1/2hp and greater motor size and can handle from 5 to 20 quarts in volume (depending upon the model). BL model mixers are available in commercial models which are UL and NSF Certified. If one is considering a commercial application then one should acquire a commercial device
2) BL mixers differ in the removal of attachments and bowls when compared to TH mixers. Attachments on the BL design extend into the bowl and therefore the mixed ingredients (even with the bowl lowered). Therefore the attachments must be removed prior to the bowl being removed, this requires some practice to accomplish without making a mess. Second is the bowl itself, as its attached using a three point locking mechanism which requires some skill to get properly locked into place and equal skill to remove.
3) BL mixers hold higher volumes of mixed ingredients, therefore their bowls are heavier. Consideration must to be given to the ergonomic advantage humans need to handle the increased weight of the BL mixer bowls when they are laden with mixed ingredients.
A household decision about which mixer to purchase, centers around the need to handle heavy mixed volume, kneading thick dough, repetitive use, and finally additional attachments. Constant kneading (daily occurrence) of thick bread dough or constant mixing (daily) of volumes greater than 4 quarts, or attachment use for heavy grinding, grating, will require a BL mixer. Without the heavy demands, a TH mixer is an excellent choice.
My husband bought me the bowl lift because I wanted to have the water/ice jacket. Turns out I have never gotten around to using the jacket, but I detest the bowl lift and wish I had gotten an artisan instead. It's real messy to remove the bowl or beater and you lose batter in the process. With my old tilt-head sunbeam, I used to lift the beaters just above the batter and turn it on low so that centrifugal force would send most of the dough off the beaters back into the bowl. Can't do that with a bowl-lift.