Dear Lulas Boss, nice name, but who are you trying to kid? Shouldn't it really be "Lula IS the Boss"? In your post you mentioned it was a joy working her.Had a litter of shorthairs 8+ years ago and ended up with 2 of them, didn't plan on it. So for that many years, had two on the ground. Each of the 2 has their own way of working afield, bringing joy to my heart each individually. Now, put them together when they act as a team, added joy, so in essence it has multiplied!
Added effort, sure. Added vet bills, yep. More poop, ok. I found it easier training 2 dogs at the same time, but not always together. I'm taking 2 dogs to the vet in 1 trip. Picking up pooh? Doesn't take twice the time once your out there. I look at it as being proficient, maximizing my effort.
Having 2 (or more) dogs is more effort, and could have its' drawbacks if you look at the glass half empty. As I look back, aside from the added joy of 2 dogs, I realize we were more efficient in retrieving downed birds.
Now that my boys are pushing 9, we picked up a pup 5 weeks ago, making it 3. She (Gretchen) follows Oskar like his shadow, and they play together, so I'm thinking I'll have help in training, more joy!
Since you asked for opinions, my two cents says get the second dog. Since dog people live longer, more dogs equals longer life in my book.