I have W70Ds and Monitor 7Cs, they are both definitely keepers. The W70Ds really shine with my tube amp and the Monitor 7Cs sound real sweet with vintage SS receivers. I'd keep both.
I have W60E's, not the W70E's (and W60D's, W60's, W90's, the Denton reissues, and a couple others), and one thing about basically ALL Wharfies from the '60's and '70 s, they LOVE tube gear (and the most-tubelike of solid-state models such as the Sansui *000X series and other models from that era). If you tried those W70E's (same as the Rosedale model) with a Fisher 500C or something similar, I think you would be very-happy with the results. Major-league synergy there. I'll never sell my W90's after hearing them with my Fisher 800C (and after recapping them with oil caps). Like all the W*0 models, sealed or ported, they have an engaging, heavily-musical quality that is rare among speaker brands, and they're also very-forgiving with average and less than average recordings. They sound great with jazz and classical, but I love them for the way they sound with classic-rock/pop and classic-funk/soul music (My W90's are off the frigging chain on that stuff... All that old '60's and '70's funk/soul/R&B, it's like they were made for that music).
Another thing about the old Wharfies, they don't need much volume to shine, even the 6-driver W90's. Just a small twist of the volume knob, and they open up, smooth out, and CLEAR up. And once they're in that sweet spot, the sound becomes effortless, with good PRAT. Very-laid-back, but full of life. And with that 15" woofer, I imagine the W70E's are pretty-effortless. With the right amplification and placement (including the tweeter being at ear-level and cabinet being far enough from the wall, the latter being the case with only the W*0E series), any of their large-sized W*0-type models will put out some truly-excellent sound. I like my W60E's. I just use my W90's so much that I really haven't looked back. Those W70E/Rosedales should go toe to toe with AR's best similarly-sized models (I've heard from a couple people who say their W60E's sound better than the AR3a. The W60E is an excellent speaker, so it's larger sibling must be even better. The only one I'm not sure about is the W80, their TOTL in '71. A strange model with a sound-deflecting ring that I think you could aim wherever. But it must surely share the sound-signature of the others in that series.
And Wharfies in general are non-fatiguing, all-day-listening speakers (although you should already know this by now). Also, most/all vintage Wharfedales tend to reward precise placement. The most-important thing is to get them equal distance from the centerpoint of your listening spot, and I mean EQUAL. With my W90's, the magic lies within that last quarter-inch of tolerance. That's why I was surprised to hear about Polks being rather-touchy in terms of placement.