I am a PhD student and I am often faced with several ideas to explore. Two criteria often I consider in making a choice between approaches are based on the value proposition/ addition and the uniqueness of the approach. However, in the process of research (which I don't have any idea about and I am only in the exploratory phase of an idea) I have to make compromises in choosing between approaches which are not unique but add value and vice versa. I am faced with tradeoffs between the two until I find (or modify/improve) approaches that have both the qualities. My question is to the experienced researchers to share their strategies when they had to choose among approaches based on these two parameters. Which one among the two help in quicker publications or acceptance rate?
Ideally, you don't choose. A "unique" approach that doesn't add value isn't worth much. Solving a problem using off-the-shelf techniques also isn't worth much. What you should aim for is a unique approach that adds value to the research landscape in your field.
But if you must choose, work toward your strengths. Do you carry a hammer and look for nails, or do you carry nails and look for hammers? If you're better at finding new tools to attack hard problems, then you're more likely to come up with unique approaches. If you're better at finding hard problems to successfully attack with a small suite of tools, then you're more likely to add value to those tools. I know lots of successful researchers in both camps.
You are optimizing the wrong function. Your primary goal should be to produce the highest quality, highest impact research, not to maximize the number of lines in your CV. One good high-impact paper is worth far more than a pile of publications that nobody cares about.
It probably depends on the field and the journal you're aiming at.
For small, low-impact journals, it could be sufficient that an idea is new. If your ambition is not very high, you can submit to such a journal. You might not need to show that the new idea is all that useful.
For more prestigious journals, new is not enough. You need to show that it's actually useful in practical situations or adds something significant. If you want to aim for good journals, then added value is important. However, it should not be a small added value; it should be a significant added value.
If it's not new and the added value is small, probably you'd need to improve the research until you have something more substantial.