At 7 months out for mid-June to mid-August for studios:
1.Usually open: BWV pool/garden view, BLT lake view, Poly, BRV, AKV standard and savanna view at Kidani and often at Jambo, OKW with the sometimes exception for rooms in the near Hospitality House booking category, and SSR.
2. Usually impossible to get: AKV club level and value.
3. Very difficult: BLT standard and BWV standard but you might get lucky and sometimes find three or possibly four consecutive days open particularly during DVC's second lowest demand time of the year that runs from July 7 to July 31.
4. Difficult: BWV boardwalk view and VGF (both standard and lake view) but you can sometimes find openings and even potentially a week during that July 7 to 31 time.
5. Not quite as difficult: BCV and BLT Theme Park view which are usually a 50/50 chance during that period except little chance for holiday time and lower chances in June and Aug after first week.
6. Jury is still out: CCV, the newest resort where it appears there can be issues for studios, particularly those with only showers about half the time but that could change.
7. As to non-WDW resorts: Aulani is near impossible mid-June to July 5, but thereafter ocean view has high chance of being open, Pool and Island Garden view about half the time (and often one of those is open when the other is not), but standard view (and hotel rooms) are usually mostly filled. VGC and HH is usually difficult but sometims there are openings if you book very quickly at exactly 7 months out. Vero is not quite as difficult but the problem there is you will have a hard time finding more than few days in a row open.
As to choosing a home resort where you usually cannot book until 8-10 months out for that June to August period, avoid purchasing BLT if you usually want standard view, AKV if you want value or club level, BWV if you want standard view, BCV if you want holiday time, and VGF and BWV boardwalk view if usually reserving less than 10 months out.