I.B. Horner was my first Buddhist teacher. I can’t say the experience was wholly pleasant. She had a nasty habit of snapping at her students, and this lost her more than one of them.
Looking at her translation, I can see why it’s no longer popular. I picked at random a few paragraphs from toward the end of MN 74.
Evaṃ passaṃ, aggivessana, sutavā ariyasāvako sukhāyapi vedanāya nibbindati, dukkhāyapi vedanāya nibbindati, adukkhamasukhāyapi vedanāya nibbindati; nibbindaṃ virajjati, virāgā vimuccati. Vimuttasmiṃ, vimuttamiti ñāṇaṃ hoti. ‘Khīṇā jāti, vusitaṃ brahmacariyaṃ, kataṃ karaṇīyaṃ, nāparaṃ itthattāyā’ti pajānāti. Evaṃ vimuttacitto kho, aggivessana, bhikkhu na kenaci saṃvadati, na kenaci vivadati, yañca loke vuttaṃ tena voharati, aparāmasan”ti.
Tena kho pana samayena āyasmā sāriputto bhagavato piṭṭhito ṭhito hoti bhagavantaṃ bījayamāno. Atha kho āyasmato sāriputtassa etadahosi: “tesaṃ tesaṃ kira no bhagavā dhammānaṃ abhiññā pahānamāha, tesaṃ tesaṃ kira no sugato dhammānaṃ abhiññā paṭinissaggamāhā”ti. Iti hidaṃ āyasmato sāriputtassa paṭisañcikkhato anupādāya āsavehi cittaṃ vimucci.
For ariyasāvako, Bhikkhu Bodhi has “noble disciple,” which I would say is pretty much the standard that we’re used to today. Thanissaro has “disciple of the noble ones,” which, okay, you could make a case for. But Horner just has “disciple of the ariyans.” That’s making the reader do a bit of work.
For abhiññā, BB has “direct knowledge,” Thanissaro also has “direct knowledge,” but Horner has “super-knowledge,” which sounds a bit esoteric.
For sugato, which I admit is difficult to render into idiomatic English, BB has “the Sublime One,” Thanissaro has “the One Well-gone” (which is literally correct, but not good English), and Horner has “the Well-farer,” which isn’t particularly helpful. I would suggest “the Accomplished One.”
Where BB has “through not clinging,” Thanissaro has “through not-clinging” (who would use “not-clinging” as an English noun?), but Horner just has “without clinging,” without the causal sense.
Finally, for āsavehi, BB has “taints,” Thanissaro has “fermentations” (!), and Horner has “cankers,” which is decidedly old-fashioned. (And when was the last time you heard anyone complain about their “fermentations”?) My preference there would be to leave āsava untranslated, since it is such a technical term, and to explain it in a note somewhere in the book.