Yes, TransType is very good. There a couple of other translators that also do good job.
It also gives the option of converting to off and can group them in families so FEX gives you a more concise selection in the Adobe CC apps.
Can't quite guess how "converting to off" was supposed to read. The fonts likely (but not necessarily) already have family names so the typefaces would group together, but the further we get away from the old styles of fonts into Unicode, the more of these odd issues seem to be appearing. The biggest being placement of the non-Latin characters.
If you're counting glyph cells starting at zero, the space character is at ordinal position 32. After that the most standard punctuation marks and numbers. Then the letter A at position 65. It then runs through all upper case letters, followed by a few more standard glyphs and then all lower case. No real issue there since all fonts should have these glyphs in the same spots whether then have an assigned Unicode value or not.
The problem with old fonts and up-to-date Unicode aware apps is the position of less commonly used glyphs. Here's Garamond, both by Adobe. Type 1 PostScript first, OpenType second.


The most obvious difference is there are no glyphs before the space character in the OpenType version. 1/2, 1/4 and others are before that in the T1 PS version. Those have predefined Unicode positions and will always be in the same ordinal position. But in an older font like the T1 PS version, they can be wherever the vendor making the font felt like putting it. Basically, there were no rules or conformity of any kind for extended glyphs.
Many of the extended glyphs shown here line up well with the OpenType version, but I've seen some horribly jumbled fonts. One was so bad, a person sent me the font to look at because it no longer worked for them. It would display correctly, but print alphabet soup. Looking at it in FontLab (as above) I couldn't believe the font ever worked. I rearranged the entire thing to put glyphs where they were supposed to be, assigned Unicode values to them and saved it as an OpenType PostScript font. Sent it back to them and they were extremely happy. It was a corporate font they were required to use for their government contract work and had to get it fixed.
The point of all of that is because those older fonts would puts extended glyphs in positions essentially chosen at whim, you many have seen 1/2 where you expected in a very old version of Word, InDesign, Quark XPress, etc., but when you opened that old document (even with the original font open), the 1/2 glyph may not show. That because, the new version of the app is looking for 1/2 in its Unicode position, but that's not where the glyph is in the old font.
The good news. As long as the font cells have their proper names assigned to them, when you convert the font to OpenType, the converter app will move all of the glyphs to their Unicode positions for you.