Typically the more sulfite solvent action, the less sharp the edges of the silver grains are. It depends on quite a few variables, including developer activity, sulfite content etc. D76 and D23 are of this type of developer (solvent developer). D76 is more active than D23 so the solvent effect is not quite as great. HC110 is a solvent developer but a little different. The dilution can have a significant effect though. If you dilute D76 or D23 you get less solvent effect.
Regarding 777, well, it is a special case only in the sense nobody is 100% sure what the formula is, and, at least partially because of that, some people believe it to have magical powers.
A few things you should know about this developer.
1. It is used as a deep tank replenished developer.
2. It is expensive and the minumum size makes several gallons.
3. It contains paraphenylenediamine which is toxic and a known carcinogen. At the very least this chemical can cause severe dermatitis and is a cross-sensitizer.
4. AFAIK, there is no known MSDS for it and so you are operating blind as to its health risks.
5. You may have truble getting it shipped internationally.
You may ask why without a MSDS people know it contains PPD. The give away is the very distinctive smell of the developer.
A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.
My quest for info about 777 led me to a tiny little book by Morris Germain and his formula for Germain Finegrain, which had 7g Metol,7g PPD,70g Sodium Sulfite and 7g of Glycin.. It's been my first choice for all films for about six years now.