Privado Recommendations

I will be visiting BsAs soon and trying to narrow down my choice of privados to a manageable few. Not easy as there are lots of reports here but very few positive ones in the last 6 months.

So I'd like to ask any veterans here a few questions:

1) Any recommendations, based on recent experience, of privados with a good selection where I can make the initial contact by phone in English?

2) Is it even necessary to contact them by phone first? Or can I just show up without prior arrangements?

3) Parsing of addresses: Does "Junin 1631 3-D" mean Junin Av., bldg. #1631,3rd floor, apt. D?

4) Is there any difference between "Masajistas Sensuales" and regular privado girls?

Thanks in advance.