Hi, I've have Springer Spaniels also and found that keeping them short was about as good as my non-shedding doodle. However, you need to know that many doodles do shed - one of mine sheds tons - way more than my Springer ever did. :-} The reason you've seen such a difference in doodles you have met is because they are mixed breed dogs and as such there is no standard.
If allergies are a concern, you need to be aware that there is truly not a hypoallergenic dog breed, however 'non-shedding' dogs tend to be more allergy friendly. Here is a link to the most allergy friendly breeds: http://www.justdogbreeds.com/low-shedding-dog-breeds.html
The problem is that as mixed breed dogs, every Goldendoodle or Labradoodle is different, so the fact that one does or doesn't affect allergies doesn't mean that another one will affect in the same way. The protein that causes dog allergies is called KNF1, and it's present in varying amounts in individual dogs. With mixed breeds, even within the same litter, you can have wide variations, and there is no way to know that until the dog has his adult coat. http://doodlerescue.org/forum/topics/the-truth-about-dog-allergies-and-doodles
Here is an article about determining allergy levels with a particular doodle. http://www.doodletrust.com/education/doodle-alergy-myth No one should make a guarantee that a doodle is or will be hypoallergenic - this is marketing hype. If you are still interested in adopting a doodle (that may or may not be allergy friendly) be sure to read our DRC ADOPTION POLICIES AND PROCEDURES. http://doodlerescue.org/notes/DRC_ADOPTION_POLICIES_AND_PROCEDURES NOTE: You MUST have had a dog as an ADULT with VET RECORDS for that dog in YOUR own name.