I have a 627 with the 5 inch barrel and you can absolutely, positively shoot it with or without moonclips.
If you find the right brand of moonclips to work with your brass, the reloads can be pretty quick. On the other hand, if you practice with speedloaders, you can come pretty close to a moonclip reload on a good day.
Here in Mexican Practical Shooting, we allow you to use moonclips up to Expert Class. After that, you cannot use them. This because only the very rich or very lucky (or me) can get a moonclipped revolver normally because down here everything has to come through Midnight Auto. So it would be ludicrous to allow a technical advantage (and tactical) that only a very few could ever have. Then it becomes a contest of "who is better connected" as opposed to who is a better shot.
So I have a 627, and I have the moonclips for it but I generally use it with speedloaders when I use it at all. We have the same rule for 7 and 8 shot revolvers: you can't use them after reaching or above Expert Class. However, we do allow them in the "unlimited" events against the automatics (which are always .380 acp or .380 Cal or Super Cal and have at best a 175 powerfactor) where the 627's actually shine because they got the poop that a .380 -- even from a fully-supported 6-inch 1911 barrel -- cannot get.
Enjoy the gun: with or without moonclips.