What do you mean by 'alternative'? Same level of IEM? There are at least a dozen top tier that can be the alternative, check out average_joe's top tier thread for more detail. I would recommend you find out the sound signature you prefer first.
Treble wise, DBA-02 actually extends further up and in comparison, ER4P sounds much smoother and less in-you-face. Mid is almost a tight, DBA-02 has more texture but harsher on the upper region. Bass wise DBA-02 is better, both in quantity and quality. While they are both analytical sounding, ER4P is more neutral (naturally) while DBA-02 is more aggressive, that's the main difference. As for iM716, it simply can't keep up with the other two so there is no need for comparison.
Can you tell me how the DBA-02 compares to the Tri-fi 10 in terms of bass, soundstage and instrument separations ? Thanks in advance.