My rule is to use pipeline for OSR<4, and for everything else use delta sigma. Pipeline ADCs are best for high data rate medium SNDR applications, like image sensors, that don't need anti-aliasing filters. Modern delta sigma modulators are best for any application requiring active anti-aliasing filters. The anti-alias filter requires some OSR, which the delta sigma modulator can take advantage of. Modern delta sigma modulators can provide SNDRs>70dB with OSRs as low as 4, and much higher SNDRs for larger OSRs.