I bought mine in January and have brewed on it 10 times. All but one of those times was doing a single batch with the short malt pipe. Contrary to what most people have described, I struggle to get over 70% mash efficiency, even for beers in the range of 1.045-1.050 OG. Perhaps I'm measuring it differently, or perhaps it's a limitation of the short malt pipe, or something else. The only full-size batch I've done also came in at 63%, but it was a bigger beer. Anyway, it doesn't bother me too much now - I just set most of my recipes to 70% and aim for that.
I think to get any sort of decent efficiency, sparging is a must (I'm very happy to be proven wrong on this, as long as you show me how!). This adds a bit of stuffing around to what is an otherwise very streamlined and automated brewday. Just something to be aware of. Also, don't trust the measurements on the tie-rod - mine were a few litres out to what is reported in the manual, and I've heard this from others too. The manual may be reporting volume minus dead-space, but whatever the case, it can throw your calculations out.
Price certainly is a big factor, not forgetting the need to get a 15A circuit installed if you don't already have one. The reason I went the 50 despite primarily brewing 20L batches is the ability to use the large malt pipe to brew a big beer, and gain on the OG by boiling it down longer. I haven't tried this in anger yet, but I'm confident it would work.
If you've got a local retailer that stocks them, or perhaps a local club with someone who has one, try and get along to a brewday and see what's involved. Whilst I don't think my brewdays are any shorter since moving from my old 2-tier 3V setup, the amount of hands-on time seems to be far less.