I did a quick synopsis of the 1/700 Kagero kits offline for Bill Liebold not too long ago, which I will reprise here. As of now, there are four sets of choices in 1/700
Original Aoshima (circa 1980) – don’t bother, it’s been surpassed by everything
PitRoad (circa 1992, new reboxings 2005) – good overall kit, decent bow form, good details, though slightly overscale (this is how PitRoad achieved its great reputation. In the early 90’s, technology allowed better tooling, though not like today. PitRoad used highly detailed masters that were just slightly overscale by a couple of percentage points that allowed for nice detail on very small parts and surfaces.), porthole indentations. The Pit-Road versions are good. Outside of scale concerns (minor), the only thing that bothers me is the shape/silhouette of the bow. The Aoshima kit does it better, and finer. The Japanese DDs have a very specific bow form and I don’t like the way Pit-Road has molded it. It can be fine tuned with some sanding.
The Pit Road Kagero kits are all popped from the same mold; some are now offered with a bottom to create a full hull, others with new decals for different ships in the class, and of course, there are early and late war versions. I believe the following kits were issued:
Kagero 1941, WL and full hull versions
Hamakaze 1945 WL, also a ltd. edition version with PE
Isokaze 1945 WL, also a ltd. edition version with PE
Maikaze 1941 WL & full hull
Yukikaze 1945 WL & full hull, also a ltd. edition version with PE
Midwar versions can easily be built from these. Do not confuse the other PitRoad Type A DD class kits Asashio/Michisio.Kasumi or Yugumo/Asahimo with the Kageros as the boxes and art look so similar.
New Aoshima (circa 2003) – beautiful hull, forecastle and bow forms, (they even managed the slight rounding of the forecastle sides as it meets the hull), accurately scaled detail. OTOH, no portholes or degaussing cable, and the issue for some modelers is that the detail is scaled so correctly that it’s almost too small to see, hence a preference for PitRoad. It’s really an aesthetics choice. I feel that the PitRoad is a little easier to build because the Aoshima version needs more added to it, portholes for instance. I actually do use some PitRoad parts, like the main (and other) rangefinders, for instance, on the Aoshima kit. Still, the Aoshima version is my personal choice every time. (note: I have a chart for the porthole locations)
The new Aoshima tooling has yielded several ships, 4 of which are sold as 1941-42 era. The later war ships can be backdated as well. Be sure not to confuse any of these with the earlier Aoshima tooling:
http://www.hlj.com/product/AOS03353 Kagero 1941
http://www.hlj.com/product/AOS03354 Hayashio 1941
http://www.hlj.com/product/AOS03408 Hamakaze 1942
http://www.hlj.com/product/AOS03407 Maikaze 1942
http://www.hlj.com/product/AOS03779 Isokaze 1945
http://www.hlj.com/product/AOS03395 Yukikaze 1945
There are also these 4 discontinued versions of which some may be in stock with different companies; the Isokaze and Kurushio come with a super detail PE fret (not bad)
http://www.hlj.com/product/AOS03396 Akigumo 1943
http://www.hlj.com/product/AOS03483 Kurushio 1942
http://www.hlj.com/product/AOS03484 Isokaze 1945
http://www.hlj.com/product/AOS03711 Yukikaze 1945
There are also late war, full hull versions for Isokaze and Yukikaze, as well as a full hull post war version for the Yukikaze as the Chinese Tan Yang. The hull breakdown is a little different, and the linoleum tiedowns are erroneously recessed instead of raised, but otherwise, it's the same tooling.
New Fujimi (2010) – just in, not built yet. Fujimi has tried to combine the scale of the Aoshima with the detail of the PitRoad with a reasonable amount of success. OTOH, the kit seems over-engineered with too many parts. It is, by far, the most complicated to build (ex. The bridge has so many pieces that there even more seams to fill than on the PitRoad version), some details wrong. I hate how they’ve engineered the prow (good chance of wrecking the lines of the bow). Late war version with degaussing cable and raised, sealed porthole covers but could be backdated with some scratch-building. It may be a good choice for the late war versions; I won’t know until I actually build one.