I absolutely love a good debate so in response to the last few posts....
I actually contribute to a number of forums and whilst I've joined this one, my intention is to contribute here on a regular basis now I have access, I just happened to stumble across this post which I believe we can really add value to. Whilst we may be a vendor contributing to forums like this give us visibility of what's really going on in the market and the opportunity to enter in to discussion with our peers in the industry regardless of which camp they have a foot in (e.g. Windows or Linux etc).
I actually come from a sales and commercial back ground and have spent the last 17 years selling a mix of both Microsoft & Linux based solutions and I'll openly admit that in the right circumstances there are benefits of both approaches and personal preference can also play a large part (e.g. some with Windows skills is almost certainly likely to promote Microsoft Small Business Server and a Linux specialist will be a solution that has been developed on Open Source components).
Based on my personal experience I genuinely believe that Linux based solutions are (i) more commercially attractive (ii) more reliable/resilient (iii) more secure (iv) provide virtually the same level of functionality (with our offering considerably more as their is a complete security suite included).
With regards to vendor lock in you've only to look in any techie forums to gain an insight in to the technical issues and challenges you guys face dealing with Microsoft Small Business Server on a daily basis, Microsoft usually get 'kicked' on a regular basis re security issues and other issues and whilst you may be able to change support company there is not a damn thing you can do about any of the underlying issues.
In our case our appliance is based on a number of open source components which has been developed over a 3 year period and should we go belly up as terms in the above post we would simple provide customers with access to the code and support can then be picked up by any developer/IT support company who possess LAMP (Linux Apache, MySQL & PHP) skills.........e.g. a skill set that is readily available where there are just as many local vendors of Microsoft so we don't really see any risk here. Linux/LAMP skills actually cost the same as Microsoft skills so this isn't a valid argument either............although there is a considerable amount of false perception in the industry (on all sides). So we've put steps in place that protect our partners and customers.
If you currently have "a hotchpotch of unix/linux systems" then really you can't expect anything other than a load of issues and downtime etc equally you could have a hopscotch of Windows based systems and be in exactly the same boat, regardless of the technology solutions need to be well designed, well developed, well implemented and well supported and whether your looking at Windows or Linux technology it isn't going to make a difference.
Just going back to support as an example in our business we operate as an MSP (Managed Service Provider) and our service included 24x7x365 remote monitoring, technical support and even guaranteed replacement hardware (pre configured) on site within <4 hours in the unlikely event of a failure (plug and play customers can be up and running in 5 mins) and all of this is supported with documented service descriptions and SLA's..........when you use local resellers levels of skill, experience, expertise all vary greatly as do their definitions of 'support' which range from give me a call if you need me and I'll see what I can do right through to some highly professional organisations who have well designed support processes..........again its not the technology that makes the difference its the people.
Wise Guy is absolutely correct when he says standardisation offers a lot of benefits (infact its vital) and in our case every single appliance we have is a completely standard build. All appliances run the same operating system configuration, same application stack (customers can use as much or little of the functionality as they need) and are managed/supported using the ITIL best practice methodology - There is a considerable difference here between our approach and what an independent developer may pull together where every solution is bespoke and support is a little undefined.
Google Apps are clearly another good option and many smaller organisations choose to use them as there simple to use, commercially attractive and provide essential services.............until Google (or Hotmail or Amazon or BT) have a 3 day outage like they did 4 months or so ago then your stuffed and to make matters worse there is no one to speak to your in the grey area of email support and support portals so yes there cost effective but are they always the most appropriate solution?
Interestingly Microsoft's strategy is now to focus on mid market businesses as they are starting to loose ground in the small business sector with a whole raft of SaaS and Appliance based solutions quickly gaining ground some of which include....
IBM Lotus Foundations offering -
http://www.lotusfoundations.com
So next objections please against Linux based solutions, lets see if anyone can put a strong argument up...........