IMHO, the REO is a fine, fine mod - the Nemesis of squonkers, if you will. The grand model has the catch cup, which can bother some folks with larger atties, but the P67 has a flush 510. As for the hot spring, it's a safety feature and nice to have just in case (why wouldn't it be nice?).
It's also like the OG VW Beetle, which is to say it's beloved and tends to engender an emotional connection. Like the Beetle, this is largely because of the balance of practicality, personalization, and (when it was introduced, at least) uniqueness. All good things. Add in a very supportive manufacturer and an enthusiastic, knowledgeable community and you've got a very good place to be in vaping. Particularly for someone new to rebuilding, mechs, or squonking, which the OP indicated they were.