K, just woke up and thought id post since I contributed to that 2 hr CAP discussion and that refined my current thoughts.
Firstly, I am 100% throwing full support to an Electric type. This doesn't mean that I want mono electric, just that I think Electric is a good typing to start with, and then we can think further ahead. Electric does not resist water attacks, which is a downside, however it does threaten rain teams as it can hit many abusers for super effective damage, as well as being an excellent switch in to Tornadus. Zapdos and Thundurus-T have already proven to be frustrating for rain teams, and its always possible to address a water resist / immunity via a secondary typing or ability later in the process.
but SubCM or CM Refresh Latias are practically impossible for a Sun team to actually kill
This is actually a good point, as Genesect was one of those pokemon which checked dragons for sun. I think Volcarona tho is one of those classic sun abusers that can win 1 on 1? I also think that Birkal is trying to say that counters for Sub CM Latias already exist (surely its not just Tyranitar?), but sun teams lack the slots to handle it ergo, we can give CAP 5 the ability to fill a teamslot or two giving sun teams the freedom to include a pokemon that can handle Lati@s. (I think Reach and I disagree mostly on what type to target between Dragon and Water so I guess this makes my reply a little moot)
I will always, always be reluctant to have CAP 5 hard counter dragons such as Lati@s since they are the best sun checks in the game, and I think there is an element of risk
involved, especially if CAP 5 also has a good matchup vs Rain. If we nerf / weaken / hit both Rain and Dragons, Sun teams become dam difficult to beat since we just removed 2 of its biggest vulnerabilities. Also, I think Dragons do a fine job at checking both sun and rain teams, as well as other stuff like Breloom, and do not like the possible uncertainty CAP 5 could create if we attacked the dragon type. Sure, Sun teams have the ability to take water moves, but its still a very tough matchup, as Venusaur needs sunlight up to take water attacks (and most water types carry Ice Beam anyway) and Tornadus can be a real bitch.