I've been using SEnuke(X) for about 6 months to a year... To give you an idea... I run it on a fast O.C. quad core, ddr3, raid-0, windows 7-64bit PC using a large backup shadow drive. My internet is about 30mbps.. I download at about 2.5MB a second upload at about 1MB a second.. Needless to say this thing runs well even though I'm speed-capped when using proxies. It runs almost equally as well on one of my laptops though. (i get the same success rate with the same number of open submission windows)
I have mixed feelings about SEnuke in general but IMHO it is well worth the price tag. If you know your stuff with SEO SENuke is pretty easy to pick up and use (especially with the wizard) compared to other programs. Because of it's popularity here is a lot of learning material out there so learning comes quickly to people who are inclined to figure it out.
I still use other programs, but SEnuke has always been a fairly large part of my core SEO and it's been working well for me. Granted, you're still going to have to go out there and create other (better) backlinks, and eventually if using a link pyramid pepper some of your higher tier sites with links... But it does a LOT of the simple legwork for you. (uploading vids, account creating, profile linking, simple article posting, etc.) The new X version is great to just set and forget most of the time although there are still some bugs so you need to keep an eye on it for now. On the other hand, if you are good at connecting the dots you can outsource everything SEnuke X actually does but for cheaper (and more effectively).
If you have been reading up on the program the "indexer" isn't as crazy as they make it sound. + With just the basic subscription you are capped at 50 urls a day which is very low. And it could take upwards of a month to get actually "indexed". They also claim you get "link juice" from the indexing process but that scares me slightly. (having all our links put on large auto-blogs or however they do it now-a-days after the panda update)
Keep in mind too thing is a beast when it comes to eating through your captcha balance. If you do get it you will be refilling your balance quite often. And in case you are wondering... Private proxies aren't as necessary with the new version as much as it was for the legacy version.