If you can get the sounds you want out of one, go for it, but try it first. A lot depends on the type of music you are playing and the sounds you want.
You'll never get a big Marshall sound out of a modeler, but the best ones will get close - but putting your guitar through a speaker will almost always give you a better sound than a DI path.
I got a Behr V amp (2 x 12) as my band-practice amp, so I don't have to haul my Line Spider home every time I want to record. The Behr is adequate, at best. The built-in effects which can only be accessed for changing via a MIDI controller are sucky.
My reverbnation site: http://www.reverbnation.com/mikebirchmusic
Youtube: http://www.youtube.com/mikebirchmusic
Facebook: http://www.facebook.com/mikebirchmusic