The Voltage def seems like a more freeride, park oriented bike. i havent ridden a slash but from what ive heard its pretty similar to the covert. the covert is transitions all mountain freeridey bike, and the bottlerocket is their freeride bike. but i rode resort DH and bike park stuff all last summer with it and it definitely likes that more than all mountain riding. it rides low in its travel and really gets stable when you wanna plow through rough sections. and riding around the bike park stuff it really wants to pop around and jumps very very well. its super lively. just build it up like a freeride bike and you got something that can do both very well. i rode 6 different AM bikes last summer before i bought it, and the covert really felt by far the most freeride oriented.
i put a CCDB on the rear and it was a huge improvement, definitely a good idea to go for a coil shock rather than air. that and get a lyric coil or marzocchi 55 fork or something more freeride oriented. wish i did, im switching from my 36 talas soon.