I captured these photos using an iPhone 5s, Camera + with Olloclip macro lens. I wonder, would it give more sharpness/details if these were taken using a DSLR with a macro lens?
Assume printing at approximately A5-size, 148 x 210mm (5.8 x 8.3 in).
The iPhone attachments can produce reasonably good results. But, quality of those attachments ranges far and wide. Some are super cheap, going so far as to use plastic lens elements instead of glass.
Assuming your attachment is of good quality, then the usual iPhone/DSLR differences apply. The iPhone, having such a small sensor, needs an incredibly well lit environment to take a low noise photo. This may simply not be possible.
Additionally, macro attachments require you to be very very close to your subject. If your subject is alive, you're probably not getting the shot as you'll scare it off.
The DSLR will have different macro focal lengths, allowing you to pick how far you want to be to produce a 1:1 shot. You'll also benefit from the use of a good tripod and macro focusing rails, if needed. Additionally, flash can be used to greater effect.
To sum it up, in a well lit environment with stationary objects, an iPhone and DSLR may be able to compete head to head in terms of image quality. Outside of this, the DSLR still gives you the ability to get the shot, while the iPhone will leave you looking at the photos others have taken (with their SLR).